Bulletin of the American Physical Society
APS April Meeting 2019
Volume 64, Number 3
Saturday–Tuesday, April 13–16, 2019; Denver, Colorado
Session S01: Poster Session III (14:00-17:00)Poster
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Room: Sheraton Plaza Foyer |
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S01.00001: ASTROPHYSICS
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S01.00002: Solar Energy and Dynamic Maria Kuman We currently believe that the energy of our Sun comes from nuclear reactions in its core. However, measurements show that the temperature of the solar corona is millions of degrees Kelvin hotter than the sun’s visible surface. Also, prominences bringing solar matter from deeper areas are much cooler. These data demand revision of our perception about the energy source of our sun. If the solar corona is hotter and the solar core cooler, obviously the sun burns what is outside of it. The postulated by Einstein space-vacuum is curved by the gravitation of the Sun, but vacuum=nothing cannot curve! The detected in 2017 waves from two merging Black Holes 1.3 billions light years away (LIGO project) require substance in which these waves could propagate. We offer here a model of solar dynamic, in which when the sun spins clockwise, it sucks energy from outside and becomes active and when the sun spins counterclockwise, it releases energy and becomes low active. This explains the alterative switches of high and low activity of the sun, known as periodic switches of the magnetic poles of the sun, which are basis of the alternating warm periods and Ice Ages on earth. |
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S01.00003: Why are the Earth Magnetic Poles Not Periodically Flipping Like the Poles of the Sun? Maria Kuman The spinning of sun and earth induces their magnetism and determines their magnetic poles. The magnetic poles of the sun are periodically flipping like a clock, which means the direction of spinning of the sun changes periodically from clockwise spinning when the sun is active (warm periods on Earth) to counterclockwise spinning when it is not active (Ice Ages on Earth). However, the magnetic poles of the earth flip irregularly, which means the direction of spinning of the earth change rarely and irregularly. If the dynamic of the earth’s electromagnetic field lacks the strict periodicity, it is because our earth is cleft (as found by earth satellites) and its center of mass is not in the center. Based on ancient texts, explanation is offered of why our earth is cleft. Simulating theoretical mathematical models predicted periodic reversal of the magnetic polarity of both the sun and earth because they didn’t consider the irregular shape of our earth. |
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S01.00004: Origin of the Life on the Primeval Earth Seyed Mohammad Taghavi Ahrami, Hassan Gholibeigian It seems that the Si. Stone may have been the key to the origin of the first protocells on the primeval Earth. On the other hand, on the following arguments the semipermeable layer water-filled by air bubbles covered by soft clay can’t be the origin of the life. The first is that, there was no soft clay on the Earth for enveloping the water-filled air bubbles. There is still no erosion of the stone materials in that time. Producing the soft clay from erosion of stones occur during few billions of years later. Secondly, there was no air only water vapor, ammonia gases, H2, CH4 and other hydrocarbons in the form of saline in the interior of the hot Si. Stone. The water vapor including the mentioned above items sediment inside the hot Si’ layers during the vaporizing the water. The temperature of the process inside the Si. Domain should had been about 150- 200 degree of the centigrade. Tاhen these accumulated black sediments can be origin of the first protocells. |
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S01.00005: Unitary Entities may comprise Space Time Richard M Kriske This Author had previously proposed that charge may evaporate, say in Positron, transforming them into "Holes", the "Holes" would draw electrons toward them, giving rise to the expanding effect that is seen in Thermodynamics. "Holes" may give rise to quantized, Unitary entities. Feynman once said that a truth table, for the OR function, can be looked at in this way; T OR T is T, T OR F is F, F OR T is F, and F OR F is F, so if one start from the conclusion of F, it can't be determined which argument was used to get to F. It turns out that "Deductions from a Conclusion" is an old art, and is part of the Human Experience, and is seen everyday in the Courts and in Politics. This Author spent a great deal of time studying logic, and was surprise that "Deductions from a Conclusion are commonly taught in Law School, and can be looked at as a Physics Theory, at least for winning arguments. So arguments (or Lies of a certain sort) are Quantized, they follow the math of Unitary Entities. One could claim that the reason that they show up, is that entities may travel backward in time. So certain outcomes are fixed, and once fixed, quantize the system. |
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S01.00006: High resolution three-dimensional hydrodynamic jet simulations of radio-loud AGN Nicholas C Juliano, Paul J Wiita, Terance J Schuh, Geena Elghossain, Nicholas Tusay, Xuanyi Zhao We showcase a set of increased resolution three-dimensional hydrodynamic relativistic jet simulations relevant to extragalactic radio galaxies and quasars. We compare these results with our earlier simulations performed at lower resolutions. By doubling the number of zones per unit cell (or jet radius) from 10 to 20 in the Athena code, we can better identify turbulence in the jet cocoons and shock structures within the jet. These allow us to more confidently characterize jet stability based on a few key parameters, such as the jet’s Lorentz factor and the density ratio of jet matter to the ambient medium. The greater detail allows us to better categorize each jet’s outcome as either a Fanaroff-Riley I (jet-dominated) or FR II (radio lobe-dominated) active galactic nucleus. We also focus on the differences in runs at higher and lower resolutions when all other parameters are kept the same and note greater jet turbulence and a decrease in cocoon symmetry at the higher resolution. |
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S01.00007: Simulation of Fe II Emission Spectra in Active Galactic Nuclei Swaraj S Tayal, Oleg Zatsarinny Accurate radiative and collision atomic data for a large number of lines in a broad wavelength region from the infrared to ultraviolet has been used in numerical simulations of Fe II emission spectra of Broad Line Region of Active Galactic Nuclei. The analysis of Fe II emission spectra provides useful diagnostics of physical conditions and Fe abundance in the gas. We investigated Fe II emission spectra using self- consistent photoionization spectral synthesis code CLOUDY. Our numerical Fe II ion model includes lowest 340 fine-structure levels of the 3d64s, 3d54s2, 3d7, and 3d64p configurations plus some lowest levels of the 3d54s4p configuration and predicts 57630 Fe II emission lines. Our model incorporates experimental energy levels and transition probabilities where available and updated reliable radiative and collision rates from our recent calculations. We have studied variation of Fe II emission with radiation field, density, temperature, and Fe abundance physical processes in the emitting regions. Our 340-model Fe II spectra are compared with available other models and observations. |
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S01.00008: Hierarchical Structure Formation Using Quasars and Lyman Alpha Forests Zaphanlene Y Kaffey In this study, we seek to understand the evolution of Large Scale Structures as a function of redshift using Sloan Digital Sky Survey (SDSS) Lyman-alpha Forest data. While the SDSS has supplied a rich set of cosmic data, we focus on quasars. The quasars we observed are billions of light years away. As light traverses these large distances, it interacts with Large Scale Structures (i.e. clustering of matter in the universe at scales larger than galaxies). The specific Large Scale Structures we examine are hydrogen clouds. Since these clouds are in between us and quasars, the light emitted by quasars must interact with hydrogen clouds before it reaches us. These interactions are detected in spectral analysis as absorption lines called Lyman-alpha lines, with a group of Lyman-alpha lines being a Lyman-alpha Forest. By examining Lyman-alpha Forests, we can trace the evolution of Large Scale Structures over time crafting a deeper understanding of the formation of the universe as a whole. |
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S01.00009: Mapping the Stellar Mass Content of Central Galaxies in Dark Matter Halos John Moustakas, Dustin Lang, Megan R. Poremba, Coley M. Stillman, Ghadeer Alsheshakly, Daniel E. Finnegan, Kevin J. Napier The central galaxies in galaxy groups and clusters rank among the most massive galaxies in the universe, but a significant fraction of their stellar mass lies in the low surface-brightness and hard-to-detect outer envelope. We use new deep optical and mid-infrared imaging of a sample of more than 20,000 central galaxies obtained as part of the DESI Legacy Imaging Surveys (http://legacysurvey.org) to measure their azimuthally averaged stellar mass profiles and integrated stellar masses using state-of-the-art photometric and stellar population synthesis modeling techniques. We present new measurements of the stellar mass function and stellar mass-halo mass relation for central galaxies, and discuss the implications of our results for numerical simulations of star formation and feedback in massive galaxies. |
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S01.00010: Chebyshev spectral solutions of the orbit-averaged Fokker Planck equations for modeling the relaxation evolution of dense star clusters Yuta Ito The Orbit-Averaged Fokker-Planck (OAFP) kinetic equations provide a fundamental and accurate mathematical model for the evolution of dense star clusters. However, their applicability has been limited by the fact that numerical integrations are typically expensive, due to the time-consuming numerical treatment of the ‘collision’ integral terms and the large gap between the dynamical and relaxation time scales. In the present work, we discuss how to overcome these difficulties by applying to the OAFP modern spectral numerical methods. Spectral methods are known for their accuracy and efficiency but so far have found limited applications in stellar dynamics. They are often termed ‘global’ methods compared to ‘local’ methods (e.g. finite difference and Runge-Kutta method) because they do not rely on space-discretization. The advantages and usefulness of spectral methods will be demonstrated by showing spectral (Chebyshev) solution both for the self-similar OAFP equation (to model isolated star clusters) and the Bachall-Wolf model (for star clusters around a massive black hole). |
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S01.00011: Finding Turbulence within E+A Galaxies that Could Govern Star Formation Kay Y Edwards, Charles Liu, Nicole Kerrison, Justin Peterkin, Andrea Ortiz, Camilla Lyczko, Cecilia Vega Orozco, Jack Hymowitz, Mariarosa Marinelli, Olivia Weaver This research studies “E+A galaxies” in the international SDSS-MaNGA galaxy survey, which has so far obtained data for 5,000 nearby galaxies over 3 years. These galaxies are in the “green valley” of the galaxy color- magnitude diagram, and optical spectra that have (1) strong hydrogen- Balmer absorption lines, (2) little or no [OII] emission, and (3) a strong D4000 break. All of these qualities indicate that these galaxies have unusually large stellar populations intermediate age. So far, 39 E+A galaxies have been found. This research will have two primary objectives: <i> to study E+A galaxies identified near the Coma Berenices cluster of galaxies to see how the galaxies’ surrounding environments affect their star formation histories, and <ii> to examine the distribution of interstellar molecular gas within the galaxies’ centers, to see signs of active galactic nuclei and turbulence that could turn star formation on or off in these very interesting objects. |
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S01.00012: The Smith Cloud: Past, Present, and Future Nicolas Pichette, Felix J Lockman, Anthony H Minter The Smith Cloud is a prominent high-velocity HI cloud with a well constrained distance that allows us to derive many of its physical properties. It contains several million solar masses of neutral and ionized gas, and is on a collision course with the Milky Way disk (Lockman et al. 2008, ApJ, 679, L2; Hill et al. 2009, ApJ 703, 1832; Hill et al. 2013, ApJ, 777, 55; Fox et al. 2016, ApJ, 816, L11). We have analyzed new 21cm HI data from the Green Bank Telescope (GBT) that cover hundreds of square-degrees around the Smith Cloud. They reveal previously unknown components of the Cloud that stretch out over a wide area. In all, the Cloud appears to extend more than 40 degrees across the sky, spanning Galactic latitudes from -40 degrees all the way through the Galactic plane to positive latitudes, with a continuity of velocity. We will discuss the results of fitting trajectories to the Cloud components that establish limits on its total velocity and trajectory through the Milky Way halo: it's past, present and its future. |
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S01.00013: AMON: TeV Gamma and TeV Neutrino Coincidence Alerts from HAWC and IceCube subthreshold data Hugo Ayala Multimessenger astrophysics has become the next step to understand the high-energy astrophysical phenomena in the universe. Hints of possible detection of a gamma-ray and neutrino source were shown last year with the source TXS0506+056; however, more detections are needed. We present preliminary results on the generation of real-time (< 6 hours) TeV gamma-ray and neutrino multimessenger transient alerts with subthreshold data from the HAWC and IceCube Observatories via the Astrophysical |
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S01.00014: A Frequentist-Bayesian approach to estimating the unknown redshifts of BATSE catalog Gamma-Ray Bursts Amir Shahmoradi We present a catalog of probability density functions and estimates for the unknown redshifts of individual BATSE Gamma-Ray Bursts (GRBs). This result is based on careful selection, classification, and modeling of the population distribution of BATSE GRBs in the 5-dimensional space of redshift and the four intrinsic prompt-emission properties: the isotropic 1024ms peak luminosity, the total isotropic emission, the spectral peak energy, and the intrinsic duration, while taking into account the complex detection threhold of BATSE and potential sample incompleteness. Our modeling approach enables us to constrain the redshifts of BATSE GRBs to average uncertainty ranges of <0.7 and <1.7 with 50% and 90% probabilities respectively. We compare our predictions with the previous independent estimates of BATSE GRB redshifts and find that all previous independent reports are completely inconsistent with each other and with our predictions. We further provide plausible explanations for the observed inconsistencies in the previous estimates. The presented catalog here can be useful for demographic studies of short- and long-duration GRBs and the methodology can be adapted for studying other GRB datasets, such as Fermi and Neil Gehrels' Swift GRB catalogs. |
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S01.00015: Fast ejecta from neutron star mergers and ultraviolet kilonova precursors Coleman Dean, Rodrigo Andres Fernandez Electromagnetic counterparts to neutron star mergers detected in gravitational waves enhance localization accuracy and provide complementary information not contained in the gravitational waves. The primary optical / infrared counterpart of a neutron star merger is the r-process powered kilonova, which arises from sub-relativistic ejecta and evolves on timescales of days to weeks. An ultraviolet precursor that peaks on timescales of hours after the merger has been predicted to occur if a fraction of the ejecta moves sufficiently fast for neutrons in it to avoid capture, thus freezing out the r-process. Such fast ejecta can in principle originate from the contact interface between the two stars, but has thus far only been seen in smoothed-particle-hydrodynamic simulations of neutron star coalescence. Here I report results of time-dependent hydrodynamic simulations on a grid-based code which examine the existence of this fast ejecta and its parameter dependencies, if present. |
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S01.00016: Nuclear Criticality as a Contributor to Gamma Ray Bursts Robert B Hayes Almost 2 billion years ago, the Oklo natural criticality events from Gabon Africa are the strongest evidence we have on the temporal stability of the fine structure constant. The Oklo events also argue that natural nuclear criticality events can and do occur in nature. Given the genesis of transuranic isotopes, it is shown that this is credible and expected in accretion disk material which would give signatures identical to many measured gamma ray burst events. The nuclear reactor physics giving rise to each facet of the measured effects will be reviewed. The nuclear and astrophysics together argue that FRED and other events may be attributed at least in part to this mechanism. |
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S01.00017: Effects of Dissipation Physics on Spectra and Structure of Accretion Disks with Non-zero Inner Torque Noah Egger, Theodore Dezen We present numerical calculations of spectra and vertical structure of accretion disks models appropriate for near-Eddington luminosity black hole x-ray binaries. We found that both stresses at the inner disk and significant dissipation near the photosphere are necessary to produce the observed steep power law state spectra. |
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S01.00018: Effects of Magnetic Pressure Support on Slim Accretion Disks Frank Corral, Theodore Dezen We explored the dynamics and structure of slim accretion disks. Specifically, we studied the effect of magnetic fields on the radial and vertical structure of the flow. We incorporated magnetic pressure via a polytropic formulation as well as by measuring directly from recent three-dimensional shearing box simulations. Qualitatively, we found that both prescriptions led to increased disk vertical scale height, although we expect detailed quantitative differences to have an observable impact on emergent spectra. |
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S01.00019: Optical Monitoring of Young Stellar Objects Aman Kar, David Kasper, Hannah Jang-Condell Observing Young Stellar Objects (YSOs) for variability in different wavelengths enables us to understand the evolution and structure of the protoplanetary disks around stars. The stars observed in this project are known YSOs that show variability in the Infrared. Targets were selected from the Spitzer Space Telescope Young Stellar Object Variability (YSOVAR) Program, which monitored star forming regions in the mid-infrared. The goal of our project is to investigate any correlation between the variability in the infrared versus the optical. Infrared variability of YSOs are associated with the heating of the protoplanetary disk while stellar signatures are observed in optical wavelengths. We used the University of Wyoming’s Red Buttes Observatory to monitor these stars for signs of accretion using the Johnson Cousins filter set, over the Summer of 2017. We perform relative photometry and inspect for an image-to-image variation by observing these targets for a period of four months every two to three nights. The study helps us better understand stellar activity and establish a disk-star connection. |
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S01.00020: Understanding the production of the heaviest elements in the cosmos through the chemical abundances of ancient stars Madelyn Cain, Anna Frebel, Maude Gull The atmospheres of $\sim13$-billion-year-old stars reflect the chemical composition of interstellar gas at the time of their birth, supplying details about element formation shortly after the Big Bang. A very small fraction of these rare stars formed from gas enriched by the rapid neutron-capture ($r$-) process. The $r$-process, believed to occur during the mergers of binary neutron stars or a neutron star with a black hole, produces all the heaviest naturally occurring elements in the Universe. $R$-process-enhanced stars exhibit the same distinct pattern of heavy elements found in the sun, suggesting the $r$-process is universal. I will present the chemical abundances of three ancient stars from the outskirts of the Milky Way with varying levels of $r$-process enhancement. The stars show remarkable agreement with the scaled solar $r$-process pattern, adding evidence for the universality of the $r$-process and providing further clues to the origin of heavy elements in the cosmos. |
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S01.00021: ABSTRACT WITHDRAWN
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S01.00022: First principles modeling of radiation from Weibel turbulence Michael Sitarz, Mikhail V. Medvedev, Alexander Philippov The Weibel (filamentation) instability occurs in weakly-magnetized or unmagnetized plasmas with an anisotropic particle distribution function. It is typical of high-energy-density environments like laser-produced and astrophysical plasmas, such as in collisionless shocks of gamma-ray bursts and supernovae, accretion shocks in galaxy clusters and others. Radiation from the Weibel-generated small-scale fields, known as the jitter radiation, differs markedly from the cyclotron/synchrotron radiation and carries wealth of information about the magnetic field properties, as both theoretical and numerical studies predict. Our goal is to study such radiation from the first principles using the state-of-the-art PIC simulations. Here we discuss the techniques and first tentative results of the project. |
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S01.00023: Study of Pulsar phase of PSR J2032+4126 with pass 8 Fermi data Aishwarya Dahiwale, Henrike Fleischhack, Binita Hona A pulsar is an extremely dense and highly magnetized rotating neutron star. Their periodic rotation produces pulsed emissions and this periodicity makes them a very useful tool in various studies. Several γ-ray pulsars have been observed in the Star Forming Region of Cygnus constellation of our Galaxy by various observatories. The Fermi Large Area Telescope (LAT) has been taking data from the direction of the Cygnus region and reported multiple pulsars in the region. One of the brightest pulsar reported is PSR J2032+4126, which has been detected at both radio and gamma ray energy regime. The emission from the bright pulsars masks the emission and activities from the nearby region. Hence, in addition to understanding the pulsar, estimating the on-pulse and off-pulse periods of the pulsar can be crucial at times to understand the nearby region as well. This contribution will present the study of PSR J2032+4126 with 10 years of Fermi data using publicly available Fermi Science tools and FERMIPY software. |
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S01.00024: Improving Automated Spectral Classifications Through Visual Inspections of Outliers Alexandra Nicole Higley, Brad W Lyke, Danielle P Schurhammer, Adam D Myers One of the best ways to improve our knowledge of the physical cosmology of our universe is through observation of quasar spectra and redshift classification. My work includes visually inspecting Sloan Digital Sky Survey (SDSS) quasar spectra in order to improve cosmological parameters, improve the precision in clustering measurements for Baryon Acoustic Oscillations (BAOs) and improve automated computer pipelines. This is achieved by manually classifying the object, redshift, and any notable features in the quasar spectra we inspect, noting any peculiar cases that might contribute to revising automated spectral classifications and cosmology research. This presentation will provide the methods I have taken in visual inspection and classifications, outliers that we have found significant or intriguing, and examples of defining features that can aid the pursuits of cosmology. |
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S01.00025: Decaying Dark Matter and the Current Cosmological Data Sets Emma Cossette Clarke, Subinoy Das, Kanhaiya Pandey One possibility for the dark sector of the universe is the existence of a dark radiation component produced from a decay of cold dark matter. We have studied the influence of this decaying dark matter (DDM) on the cosmic microwave background (CMB). In particular, we examined the impact of DDM on the existing disagreement in the measurements of the Hubble constant and σ8 inferred from Planck CMB observations and determined directly using local observables, i.e. SH0ES and DES datasets. We report that allowable adjustments of the DDM model helps to satisfy the observational constraints. |
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S01.00026: GRAVITATIONAL ANGELS Evgeny Novikov Based on the quantum modification of general relativity (Qmoger), gravitational angel (gravitangel) is introduced as a cloud of the background gravitons hovering over the ordinary matter (OM). According to Qmoger, the background gravitons are ultralight and they form the quantum condensate even for high temperature. The quantum entanglement of OM particles is explained in terms of splitting gravitangels. A hierarchy of gravitangels of different scale is considered. One of the simplest gravitangel is hovering over neutrino, which explains the neutrino oscillations. A more large-scale gravitangels are hovering over the neuron clusters in the brain, which explains the subjective experiences (qualia). The global gravitangel (GG) is connected to all processes happening with OM in the universe. GG can be considered as a gigantic quantum supercomputer.
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S01.00027: Quantum/Digits-Space Time:Duel(log:digits=dimensions=bosons-exp:inflation) Cusp-Catastrophe Sephirot Cosmogony Scenario:Dark-Sector(Energy/Matter):Light-Cone Analogy to Mechanical Stress-Strain Curve Norton Siegel, Edward Siegel, Frank Nabarro Siegel[Schrodinger Centenary Symp.London(87);Symp.Fdns.Mod.Phys., Joensu(87)]Takagi[Prog.Theo.Phys.Suppl.(86)]generic “Complex Quantum-Statistics in Fractional-Dimension” explains both Zwicky-Rubin-Ford dark-matter and Perlmutter-Riess dark energy together as a dark-sector non-nth-roots-of-unity still SUSY-combines. Big-Bang explosion bosons(photons)origin in Newcomb-digit statistics log-law algebraic inversion from outside-in(VS inside-out)like beach-ball inflation starting in stress-strain curve elastic-part in all universe supercritical-cosmological-constant scenarios with elastic dark energy and photons Poynting-vectors forcing further elastic-expansion. Elastic-(E:on light-cone)-plastic(m:in light cone) phase-transition by Higgs-Englert fields spontaneous symmetry(SUSY, isotropy, homogeneity)-breaking inhomogeneity anisotropy Portevin-Lechatlier effect Luders-bands plastic-region dark-matter and regular-matter dominated(strain=curvature=G)via Siegel[J.NonXl.-Sol.40,453(80)]G…P stop-bands localize dark-matter in galaxies superclusters filaments scaffolding(analogous to prime-numbers). |
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S01.00028: Prime-Number Distribution-Function Primes Scaffolding Analogy to Stellar/Planetary Cross-Sections and Galaxies-Superclusters Web Fredric Young, E. Carl-Ludwig Siegel, Adolph Smith Quantum/Digits-Space Time:Reflection/Symmetry Duel Double(log:digits=dimensions=bosons-exp:inflation)-cusp catastrophe. Prime number distribution function pi(X)argument inversion to pi(1/X) identifies via Floquet-Bloch-Brillouin[Wave Propagation in Periodic Structures(45)]stop-band localizing primes VS. composites itineracy whose Holthaus[Physica A 341,586(04)]BEC factorization into primes resembles Fermi contact-repulsion. Euclid proof of infinity of primes starting at 2 one sees non-sharp order-disorder phase-transitions from crystal (2,3) to glass (3,5,7,11,13,17) to liquid to gas but never to vacuum due to Euclid proof of infinity of primes. Striking is the analogy of this prime scaffolding caused by stop-band localization, explained generically by Siegel[J.NonXl.-Solids 40,453(80)], to both stellar and planetary structure cross-sections and to galaxies-superclusters web.Fundamental theorem of algebra every-natural number is a product of primes resembles many-body boson gas wave function. Furthering Schumeyer-Hutchinson[Rev. Mod. and Phys. 83:307(11)] very convincing Riemann-hypothesis physics, critical-strip concentration of Reimanns data-function on critical-line Re+1/2 is inevitable dimensionless quantum 1/2 hv. |
(Author Not Attending)
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S01.00029: Two forms of black hole existence Han yong Quan Gravity is formed by curved radiation. The black hole is the most obvious celestial body with curved radiation. The black hole can make the radiation form a closed circle. In fact, there are two forms of black holes. The first form of black hole: a black hole with extremely large density and mass. This black hole rotates at a high speed (or can exceed the speed of light), forming a huge gravitational force. Not only its own radiation cannot escape, but also the surrounding radiation and other quantum are attracted. As the black hole rotates at a high speed, it forms a gravitational force against other celestial bodies, such as stars, causing the star to rotate around it, thereby forming a galaxy. We know that rotating closed air can shield air, such as a tornado, and the rotating radiation quantum can also shield the radiation quantum. The second form of black hole: this kind of black hole does not need any substance in the middle. Its formation principle is similar to that of tornado. It is the vacuum formed by the extremely high-radiation radiation quantum. The vacuum force points to the vacuum, and the huge vacuum force can make the radiation quantum around it. Rotate to create a huge gravitational force that forms a galaxy. |
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S01.00030: Conservation of angular momentum and expansion speed of the universe Han yong Quan The celestial body with absolute mass is only the universe, and the universe expands in rotation, so the angular momentum of the universe is absolutely conserved. We can also conclude that the ratio of the radius of the universe equals the ratio of the density of the universe to the inverse of the cube. The density of the universe 10-43seconds after the big bang is 1094 grams per cubic centimeter, and the density of the universe is now 10-31 grams per cubic centimeter. According to the law of conservation of angular momentum, M1V1R1=M2V2R2, where M1, V1, and R1 represent the mass, rotation speed, and radius of 10-43 seconds after the Big Bang, respectively. M2, V2, and R2 represent the mass, rotation speed, and radius. Since M1=M2, the law of conservation of angular momentum of the universe can be simplified as: V1R1=V2R2, and the deformation is: V1/V2=R2/R1=4.65×1041. The universe is not radiated outward, so the rotation speed of the cosmic edge is not less than the speed of light, that is, V2 is calculated according to the speed of light, then V1=4.65×1041×V2=4.65×1041×3×108=1.4×1050, that is, after the big bang The rotation speed of the universe in 10-43 seconds is not less than 1.4 × 1050 meters per second. |
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S01.00031: Quantum Kinetic Equilibrium Heather M Hodlin, Olexiy Dvornikov, Chad Kishimoto The quantum kinetic equations (QKEs) are quantum master equations that account for both coherent quantum mechanical evolution and kinetic evolution induced by scattering. We solved the QKEs for a simple two-state neutrino system in the hot and dense early universe where both neutrino flavor oscillation and scattering are important in the evolution of the neutrino states. We found that solutions to the QKEs point toward an approximate “equilibrium” solution where the quantum effects balance the kinetic effects. In this poster, we will assess the validity of this approximation. |
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S01.00032: A Pauli Mechanism for Dark Energy Robert B Hayes When leptons with ultralow energy are created with wavelengths on the order of or larger than the Hubble length, these are effectively frozen into place and cannot move (as the crest cannot approach a distant trough). As these are stretched along with universal expansion, they asymptotically become ever closer in energy. Being antisymmetric wave functions, they are subject to the Pauli exclusion principle and so will increasingly be subject to a differentiation in quantum numbers giving rise to an apparent force separating them spatially. These leptons are only coupled to the Hubble length which then reacts accordingly. |
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S01.00033: Preliminary Work on a Pauli Mechanism for Inflation Robert B Hayes Postulating that genesis began at the Planck scale with existence entailing all the laws of physics, a Pauli mechanism for inflation can be realized. Taking time in Planck increments then requires all fermions to sequentially have distinct quantum numbers hence tunneling to minimally orthogonal states upon existence. Baryonic particles then make these quantum transitions scaling with their radii which alone results in ⁓1020c (due to this occurring in one unit of Planck time). Uncertainty energy and successive quantum transitions result in compounded greater than light expansion which is effectively due to fermionic matter existing under Planck scale effects. |
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S01.00034: ABSTRACT WITHDRAWN
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S01.00035: Electron-Positron Annihilation Freeze-Out in the Early Universe Luke Thomas, Evan Grohs, Theodore Dezen, Chad Kishimoto Electron-positron annihilation is the final particle-antiparticle annihilation process in the history of the early universe. It largely occurs after the neutrinos fall out of thermal equilibrium (weak decoupling) and during the Big Bang Nucleosynthesis (BBN) epoch. This annihilation occurs predominantly in local thermal and chemical equilibrium, and its effects can be seen in BBN yields as well as the relativistic degrees of freedom. This work looks to self-consistently calculate annihilation rates to determine when this process falls out of equilibrium, and to estimate the magnitude of this out-of-equilibrium effect. Connecting precision cosmological measurements to tests of beyond standard model physics models requires full consideration of the standard cosmological model, including these oft-overlooked out-of-equilibrium effects. |
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S01.00036: Exoplanet Detection by Spitzer via Microlensing Events Fatemeh Bagheri, Sedighe Sajadian, Sohrab Rahvar The Spitzer Space Telescope, NASA’s Great Observatory for infrared astronomy, was launched in 2003 and is performing extremely well, returning excellent scientific data from its Earth-trailing solar orbit. The exoplanets orbiting stars can reflect part of its light. In this work, we use microlensing as an amplifier to magnify the reflection signature from the planet. |
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S01.00037: Simulating energetic neutral hydrogen in exoplanet atmospheres Jesse Han, Phil Arras Far-ultraviolet observations of exoplanet atmospheres at the Lyman alpha line reveal the existence of hydrogen atoms out to several planetary radii. The observed transmission spectrum may be modeled as absorption by atoms traveling at speeds exceeding 100km/s, much faster than typical atoms in the planet’s atmosphere. We investigate the ability of hot stellar wind protons to transfer momentum to the atoms in the time before the atom is ionized by collisions with stellar wind electrons or stellar photons. To this end, we have carried out a Monte-Carlo simulation of the interaction of hydrogen atoms with a gas of hot protons and electrons, taking into account elastic collisions, radiation pressure forces and ionization. The resultant distribution of velocities is then used to create a line profile for absorption of stellar Lyman alpha by the atoms. We compare our model line profile to Hubble STIS measurements of HD 209458b. |
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S01.00038: Exploring Mixed Sterile Neutrino Dark Matter Models Isabella A Ianora, Chad Kishimoto Recent X-ray observations of galaxies and galaxy clusters suggest the existence of sterile neutrino dark matter with a mass of 7.1 keV. In this poster, we examine mixed dark matter models, comprised of both sterile neutrinos and cold dark matter, with sterile neutrino parameters consistent with the X-ray observations. We assess the compatibility of these models with observation by calculating cosmological observables resulting from sterile neutrino production mechanisms. |
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S01.00039: ABSTRACT WITHDRAWN
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S01.00040: Dark matter from neutrinos via enhanced cooling Richard B Holmes It is widely accepted that all three species of neutrinos were in thermal equilibrium with the universe as it cooled to ~1 MeV/k, where k is Boltzmann’s constant. Further cooling of the decoupled neutrino sector occurred as the universe expanded. However, additional rapid cooling of the neutrino sector has no mechanism in the Standard Model. A modest extension of the Standard Model provides a means for rapid cooling of the neutrino sector to about mntc2/k where mnt is the mass of the tau neutrino, via a family-specific form of SU(3). The interaction requires a density of neutrinos that is consistent with conditions in the early universe for significant cooling to occur. Properties of such an interaction lead to a dark matter content of the universe between 61% and 92%. The hypothesis yields neutrinos bound into states that are analogous to baryons with a mass of 0.4±0.2 eV/c2. Pursuing the hypothesis results in a cool dissipationless state that is loosely bound near galaxies. A polytropic exponent near 2 gives a best fit to inferred galactic and cluster halo sizes and shapes, with best results utilizing a novel generalization of the equation of hydrostatic equilibrium. The Tremaine-Gunn bound is discussed. |
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S01.00041: Dark matter halos: CDM vs 2cDM inelastic dark matter Alisa K. Galishnikova, Egor M. Novoselov, Mikhail V. Medvedev A multicomponent dark matter (DM) model is a promising paradigm, which has a great potential of resolving longstanding cosmological problems on sub-galactic scales. The simplest two-component DM (2cDM) model with inelastic interactions has been shown, via N-body cosmological DM-only simulations, to robustly resolve the "missing satellites", "core-cusp", and "too-big-to-fail" problems. Here we analytically and numerically investigate the properties of the inner DM halos with an inelastic rate, n〈σv〉, being a nondecreasing function of particle's velocity, v, using the hydrodynamic equations with mass and momentum loss. We found self-similar equilibrium solutions and studied their stability, as well as studied the nonlinear collapse phase. Implications of the obtained results are discussed, in particular to the problem of the early, rapid formation of seeds of supermassive black holes. |
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S01.00042: Visualizing 2PN Binary Black Hole Spin Precession Alicia R Lima In the post-Newtonian regime, the time it takes the two black-holes to orbit each other is much shorter than the time it takes the spins and the orbital angular momentum to precess about the direction of the total angular momentum which, in turn, is much shorter than the time it takes the binary's orbit to shrink due to gravitational-wave emission. In short, the dynamics of precessing binary black holes have a strong timescale hierarchy. Given the variables identified in [1] that respect the timescale separation of the dynamics of precessing binary black holes (𝜉, J, S), we build an interactive 3D visualization routine in Python to explore spin precession. We report the discovery of configurations where one of the two spins oscillate from being completely aligned with the orbital angular momentum to being completely anti-aligned with it during a single precession cycle. Crucially, this “wide precession” happens on the short precession timescale and it is not a secular effect due to gravitational-wave radiation reaction.
[1] D. Gerosa, M. Kesden, PRD 92, 064016 (2015), arXiv:1506.03492 [gr-qc]. |
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S01.00043: Neutron Star Measurements in Third Generation Gravitational Wave Observatories Isabella S Molina, Erick Leon, Eric Flynn, Jocelyn Read Gravitational waves from neutron star mergers provide insight into the properties of neutron stars. The properties of the neutron star's matter affect tidal interactions between the stars as they orbit during inspiral, as well as the potential waves from the post-merger remnant. We analyze the noise curves of proposed future gravitational-wave detectors to determine their capabilities and accuracy in detecting binary neutron-star mergers and measuring their properties. Detectors A+, A++, Cosmic Explorer1 & 2 Wide & Narrow, Einstein Telescopes B & D, Vrt,and Voyager are compared to AdvancedLIGO. We determine the optimal frequency range for future detector's sensitivity to tidal effects from neutron-star matter. We also use several equations of state to determine the frequency ranges relevant for a clear signal to noise ratio in the post-merger. This analysis helps determine which detector configurations are best for measuring properties of neutron star matter.
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S01.00044: Improving Gravitational Wave Detection: Interstellar Scattering Correction Jakob T Faber, Daniel Stinebring, James Cordes, Shami Chatterjee, Adam Jussila Pulsar timing arrays are sensitive to Gravitational Waves (GWs). To achieve a detection of GWs, time-variable scattering observables within the dynamic Interstellar Medium must be corrected for to decrease susceptibility to highly noisy timing residuals. A semi-classical ray optics simulation with phase-tagging capabilities, as opposed to a traditional KDI, can be used to guide the mitigation strategy and understand what interstellar effects appear in both the dynamic and secondary spectra generated in our observations. |
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S01.00045: A Multi-Frequency Scintillation Arc Study of Pulsar B1133+16 Stella K Ocker, Daniel Stinebring, Barney Rickett The arrival times of pulsar radio signals at Earth observatories can be used as a clock precise enough to detect gravitational waves. Performing such a detection requires the mitigation of time-variable delays in the interstellar medium. We investigate interstellar delays using scintillation arcs, fluctuations in frequency and time of the pulsar signal intensity that are manifested as parabolic arcs in the pulsar’s secondary spectrum. While scintillation arcs were first observed almost two decades ago, the structures that cause them are still unknown. There is accumulating evidence that the scattering from many pulsars is extremely anisotropic resulting in highly elongated, linear brightness functions. We present a three-frequency Arecibo study of scintillation arcs from one nearby, bright, high-velocity pulsar, B1133+16. We show that a one-dimensional, linear brightness function is in good agreement with the data at all three observing frequencies. Using two separate methods we find that the broadening of the arc is less frequency-dependent than expected by standard scattering theory. Our results place the scattering screen at a distance that is broadly consistent with an origin at the boundary of the Local Bubble. |
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S01.00046: Pulsar Timing Arrays: learning about interstellar medium delays Didier Banyeretse, Jillian Doane, Gabrielle Agazie, Olivia Young, Maura McLaughlin, Dan Stinebring Gravitational wave detection with a pulsar timing array (PTA) must account accurately for time-variable delays in the interstellar medium. The NANOGrav PTA currently correct for time-variable dispersion delay, but not for the known effects of scattering. We are developing a technique to determine and correct for the scattering delay at each epoch. Our main observable is high-frequency-resolution dynamic spectra of the pulsars involved. In January 2018 we observed 10 intermediate-DM pulsars with the Arecibo radio telescope. The dispersion measures for these pulsars were between 50 and 100 pc cm^-3. We made observations at 430 MHz and 1450 MHz with a range of bandwidth and channel spacing. We formed dynamic and secondary spectra for all of the data sets, detecting scintillation arcs in a number of the pulsars. We present results for these pulsars, tying them in with our previous results for a lower-DM sample. We discuss how observations such as these can be used as a diagnostic of interstellar medium conditions along a particular line of sight. By comparing lower-DM and higher-DM objects we are able to assess the relative importance of time-variable scattering delays for high-precision pulsar timing. This is of value in mitigating time delay fluctuations in PTA observations. |
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S01.00047: Two Armed Spiral, Barred Spiral Galaxies , Planet And Star Forms As Well As Universe Itself May Be Universal Patterns In Nature, Appearing In A Coffee Cup On A Small Scale And In Space On A Grand Scale. Stewart E Brekke Adding some old powdered coffee creamer into instant coffee and stirring, a number of short concentric longitudinal pairs of semimolten coffee creamer orbited the rim on the surface of the coffee. The coffee slowed down, the orbits of the coffee creamer pairs decayed, tangentially accreting and attaching in their fore sections forming perfect two armed spiral and two armed barred spiral galaxies which began to rotate. Rotation was caused by the transformation of the orbital motion of the external pre-galactic arms into the rotation of the newly formed galaxies. Equation for the formation and rotation of the newly formed spiral galaxies is (Iω)new galaxy= (Iω)arm1+ (Iω)arm2. Small chunks of coffee creamer were slowly rotating on the surface of the coffee, which I imagined as pre planetary and pre stellar cores . Some short coffee creamer orbiting sections tangentially accreted these slowly rotating chunks and attached thereby speeding up the rotation . Equation for planet and stellar formation and rotation could be(Iω)planet/star = (Iω) pre planet/star core+ (Iω) orbiting section+ ...+ (Iω )orbiting section n. The universe may be a universal pattern in nature existing on a small scale in a coffee cup and on a grand scale in space with planet, star and spiral galaxy forms. |
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S01.00048: A rigorous formalism to unfold the mystery of unusual events detected by NASA sponsored balloon borne ANITA experiment. Paramita Dasgupta, Pankaj Jain We develop a general formalism to treat reflection of spherical electromagnetic waves from a spherical surface applicable to ANITA experiment. The incident wave is decomposed into plane waves and each plane wave is reflected off the surface using the standard Fresnel formalism. For each plane wave the reflected wave is assumed to be locally a plane wave. This is a very reasonable assumption and there are no uncontrolled approximations in our treatment of the reflection phenomenon. We apply our formalism to the radiation produced by the balloon-borne HiCal radio-frequency (RF) transmitter. Our final results for the reflected power are found to be in good agreement with data for all elevation angles. We also applied our procedure to investigate whether the mystery events observed by ANITA can be explained by conventional physics. Due to reflection of radio pulse at the air-ice interface, the reflected pulse is expected to be 1800 out of phase with the incident pulse. However, observations show that in some cases the observed pulse does not show this phase difference. Using our formalism, we point out that local surface deformity can give rise to unusual phase shift in the reflected pulses. |
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S01.00049: Generalized Integral Gauss's Law with Non-Spherical Distribution of Gravitational Field Flux to Interpret Tully-Fisher Relation of Disk Galaxies Te-Chun Wang A 1/r field dependence causing flat rotation curve(RC) of disk galaxies are obtained by a Gaussian surface with cylindrical symmetry where the gravitational flux distribution is converging along the radial direction of the disk plane. The Gaussian disk thickness as a dynamical variable is examined with observational evidences. The monotonically rising RC of low surface brightness galaxies(L-SBGs) can be attributed to a Gaussian disk thinning mechanism. A spherical to cylindrical transition of the Gaussian surface symmetry across a critical field (gc)~10-10 N/Kg is shown to give the exact M~v4 Tully-Fisher relation(TFR). Possible factors causing deviation from the exact TFR of the L-SBGs are discussed. The structural-dynamical relation revealed in SPARC(Spitzer Photometry and Accurate Rotation Curves ) data are compared to the field flux distribution picture. The transition from Newtonian behavior above gc existed near the bulge region of high-SBGs to Non-Newtonian behavior below gc of both high-SBGs edge and whole bulgeless L-SBGs is mapped to the Gaussian sphere-to-disk transition of the flux distribution within integral Gauss's law of Gravity. |
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S01.00050: The Argus$+$ Program: Next Generation Mapping. Robert Lim Argus$+$ is a high-fidelity 3mm atmospheric window widefield mapping receiver. The plan is for the Green Bank Observatory's receiver to be general purpose to support the U.S. scientific community. Argus$+$ will have an angular resolution of 6.5'' -- 8'', the high sensitivity enabled by a filled aperture, and a wide field of view. This maps molecular clouds within hundreds of square arc-minutes with a spatial dynamic range (map area / pixel size) of 10$^{\mathrm{4}}$ to 10$^{\mathrm{5}}$. Based off the original 16-pixel Argus receiver commissioned in 2016, Argus$+$ will allow scientists to ask key science questions about star formation and astrophysics. Argus demonstrates unique scalable array technology that could be developed into Argus$+$'s 144-pixel camera. This technology combined with GBT metrology improvements commissioned in 2018 will increase the scientific output in the 3mm window by 20x. The team tasked with creating Argus$+$ will be the original Argus team and GBO staff for combined decades of experience designing, developing, and operating instruments for the U.S. science community. The APS poster poster shall display the science of the instrument, how systems engineering was implemented in the project, possible designs, and broader impact within the U.S. community. Using systems engineering and agile techniques, the requirements, processes, and matrices were modeled for technical design and development. The instrument provides an exploration of the tools to develop model-based processes as the use of Unified Modeling Language (UML) and Systems Modeling Language (SysML) for organizational models providing an opportunity for learning techniques for managing and defining technical projects. \textbf{Contact Information:} This is an APS poster abstract for the GBO REU program, roli9512@colorado.edu, 408-510-4658 |
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S01.00051: FEW BODY SYSTEMS
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S01.00052: Self-Consistent Potentials for Low-Energy Positronium Scattering Jesse M Kinder This poster presents ab initio potentials for positronium-atom and positronium-molecule interactions. Potentials are obtained by solving the Hartree-Fock equations for a range of molecular orientations and separations, using basis sets of increasing complexity. The goal of the work is to aid in the theoretical analysis of low-energy positronium collisions, such as those carried out at the positronium beam line at University College in London in recent years. |
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S01.00053: HADRONIC PHYSICS
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S01.00054: A Heuristic Approach to a Periodic Table of Quark Composites Ajit S Hira, Jose pacheco, Ruben rivera, Jareth Baca, Alexandra Valdez, Matilda Fernandez This work extends our interest in the study of fundamental particles to the possibility of creating a “periodic table” of Quark composites, in analogy with Periodic Tables of chemical elements. In recent years, several resonance states that cannot be any type of conventional quark-antiquark mesons or three-quark baryons have been detected. Consideration of the decay modes and charges of these states reveals the possible existence of four quark or five-quark states. According to some physicists, these observations open up a new age of multi-quark hadron spectroscopy. In 2016, a team at Fermi-Lab reported evidence for a resonance state. Outside the laboratories, penta-quarks may be formed in supernovae, in the process of forming neutron stars. It should be noted that the lifetime of a particle is the direct inverse of the particle's resonance width in experiments. We have obtained results on quark composites of the type XmYn, with 1 =< m, n =< 5. Our computer codes utilize C++ and MATLAB languages to implement the formalisms of Feynman Path Integrals (FPI) for the study of the stabilities and other properties of these hadronic particles. Our research has links to the recent reports on the work of the physicists M. Karliner and J. L. Rosner on Quark Fusion. |
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S01.00055: Mest-Spacetime Center, Spacetime Structure of Gluon, and String Theory Dayong Cao, Dayong Cao MEST is a balance systemic model of mass, energy, space, and time. There is a balance MEST system between gluons and quarks. The gluon is “spacetime”. According to Einstein field equation and negative Einstein equation, there are massenergy center with massenergy structure and spacetime center with spacetime structure which has gravity of the spacetime (as negative gravity). The spacetime center structure can explain of dark matter and dark energy. A balance structure between massenergy and spacetime can explain of the homogeneous, isotropic, and flat structure of the universe. It can suppose a balance system between the sun and a dark sun (as a spacetime center of Oort cloud). And the quantum spacetime of the wave, new atomic model, and dark atomic model of the dark matter-dark energy had brought forward. A new string theory can explain of the glunos by the gravitons of the spacetime center, a structure face between the spacetime of the gluons and massenergy of quark, a gluon field as zero-point energy between a quark and an anti-quark, and Regge Trajectories, a spacetime structure (wave structure) of the quark-gluon plasma. |
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S01.00056: NUCLEAR PHYSICS
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S01.00057: ABSTRACT WITHDRAWN
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S01.00058: EXO – 200 : 241AmBe calibration source Arun Kumar Soma Enriched Xenon Observatory (EXO - 200) is ~175 kg of liquid Xenon experiment for studies on neutrinoless double beta decay. The present gamma calibration is accomplished by 60 Co, 137 Cs, 228 Th and 226 Ra radioactive sources. These sources help to give gamma calibration scale up to 2.6 MeV. We proposed to deploy a composite neutron source (241AmBe) to accomplish several goals. Firstly, it will allow to extend the calibration of gamma energy scale above the existing limit, thanks to mono-energetic 4.43 MeV gamma ray. Secondly, the source will provide better beta energy scale calibration with the help of double escape peak of 4.43 MeV gamma ray. Finally, beta decay of 137Xe is one of the primary background contribution in neutrinoless double beta decay search in 136Xe. The 241AmBe will allow to produce a clean set of 137Xe events to validate the energy spectrum and production efficiency used in simulation. The source was deployed in November 2018. The talk will present first analysis of acquired data. We will particularly discuss the procedure to optimize selection of 137Xe decay event sample. Comparison between simulation of neutron activation in the EXO-200 detector and the observed data will also be presented. |
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S01.00059: Preliminary Design of the nEXO Experiment Brian Lenardo The nEXO experiment is a proposed next-generation search for the neutrinoless double beta decay of Xe-136. The primary detector will be a 5-ton, monolithic liquid xenon TPC with a target enriched to 90% in the isotope of interest. Building on the successes of the EXO-200 experiment, the nEXO collaboration has developed a conservative baseline design with the projected capability of excluding a decay half-life up to 9.2e27 years at the 90% confidence level. Such an experiment would improve on the best existing measurements by nearly two orders of magnitude. In this talk, we will introduce this design and discuss how nEXO addresses the stringent low-background specifications using a combination of conservative choices driven by EXO-200 measurements and novel readout schemes designed to improve the noise rejection and resolution of the detector. We will briefly describe the ongoing R&D work to demonstrate the design and validate the projected sensitivity of nEXO. |
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S01.00060: A GPU Algorithm to Determine the Time-of-Flight of Protons in the Neutron Decay Experiment Nab Tom Shelton, Christopher B Crawford, David E Perryman, David G Mathews, Aaron P Jezghani The goal of the Nab experiment is to measure the little ‘a’ and ‘b’ coefficients with a precision of 10$\times 10^{-3}$ and 3$\times 10^{-3}$, respectively. Neutron beta decay is one of the most fundamental processes in nuclear physics that would allow probing of the weak interaction. In order to achieve this, a crucial requirement is determining the time-of-flight of protons with a systematic uncertainty of less than 300 ps to reconstruct the electron energy and estimate proton momentum require for the calculation of the coefficients. The data acquisition system has the potential to continuously stream the full 250 MS/s waveform data from up to 5000 events per second. In order to keep up with this high data rate in near-line analysis, we have implemented flexible algorithms that utilize the architecture of a massively parallel graphic processor unit (GPU). A comparison of the extraction algorithms for a number of filters with be presented. |
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S01.00061: A New Particle Tracker for Soft Physics in LHCb Berenice Garcia Nuclear physicists have yet to discover, in high-energy hadron colliders, is the existence of a gluon saturated state of the matter. It is theorized that when nuclei are traveling at ultra-relativistic speeds the gluon den- sity increases. For momentum transfer smaller than Q2s(x), where x is the fractional momentum of the gluon along the beam line, the gluon wave functions start to overlap producing a condensate. Unfortunately, experiments at Relativistic Heavy Ion Collision and at Large Hadron Collider are unable to discover nor study this phenomena directly, but have data that leads them to believe that it can exist. Our goal is to build a particle detector, to be installed in the Large Hadron Collider beauty (LHCb) experiment in 2025, to study the soft particles coming from the gluon saturated region. This detector will also contribute to other soft physics studies such as particle flow. At Los Alamos National Laboratory, we are building a prototype particle detector, which consists of triangular extruded scintillators coupled to Silicon Photomultipliers (SiPMs) through optical fibers. I will present the current status of the prototype preparation and tests. |
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S01.00062: Phase Transition and Bulk Properties in Nuclear Matter Adrian Gaytan Terrazas, Jorge Alberto Lopez This study uses classical molecular dynamics to simulate infinite nuclear matter and study the effect of isospin asymmetry on bulk properties such as energy per nucleon, pressure, saturation density, compressibility, and symmetry energy. The simulations are performed on systems embedded in periodic boundary conditions with densities and temperatures in the ranges f = 0.01 to 0.2fm^-3 and T = 1 to 15MeV, and with isospin content of X = Z/A = 0.3, 0.35, 0.4, 0.45 and 0.5. The results indicate that symmetric and asymmetric matter are self-bound at some temperatures and exhibit phase transitions from a liquid phase to a liquid-gas mixture. The main effect of isospin asymmetry is found to be a reduction of the equilibrium densities, a softening of the compressibility and disappearance of the liquid-gas phase transition. A procedure leading to the evaluation of the symmetry energy and its variation with the temperature was devised, implemented and compared to |
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S01.00063: ABSTRACT WITHDRAWN
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S01.00064: RICH DETECTOR AND SIMULATION OF AEROGEL TILES Nicholaus L Trotta, Fatiha Benmokhtar A Hybrid Ring-imaging Cherenkov Detector (RICH), located in Hall-B at Jefferson Lab, is used to identify charged subatomic particles such as pions and kaons. RICH uses the momentum of resulting jet particles from electron scattering on a fixed target. These particles traverse a radiator called, Aerogel in this case. Aerogel is a dielectric material made up of silica and residues of metal oxides. Placing a beam of charged pions at 6 GeV behind the aerogel will produce Cherenkov radiation in the UV to the visible range. When a charged particle travels through the aerogel at a very high speed, the particles inside become dipoles. This polarization stretches the shape of the particles and if the incoming particle is moving faster than the speed of light in the medium, Cherenkov radiation is produced. My work consisted of the partition of the aerogel tiles for the RICH detector and the study of emitted Cherenkov radiation. This process is important for event reconstructions that will help with particle identification. Status of the RICH detector will be presented. |
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S01.00065: Nuclear Level Density according to Fermi-Gas and Constant Temperature Models Amaru Alzogaray, Josselyn Velasquez, Alexander Ahmann, Roman Senkov The knowledge of the nuclear level density is necessary for many practical applications including astrophysical reactions. In this work we investigate phenomenological approaches to the level density, including popular models, such as Fermi-Gas, Back-Shifted Fermi-Gas and Constant Temperature. We compare the level densities obtained in these models with the Shell Model calculations. The main goal of the study is to estimate the parameters of phenomenological models and justify their status as reliable tools for realistic applications. |
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S01.00066: Performance of a Prototype Single Atom Microscope for Nuclear Astrophysics Ruoyu Fang, Benjamin Loseth, Jaideep Singh The Single Atom Microscope is a novel detector that is under development for measuring small cross section nuclear reactions that are influential in nucleosynthesis. Utilizing inverse kinematics, the product atoms of the nuclear reaction are captured in a thin solid noble gas film prepared on a transparent sapphire substrate under ultra-high vacuum and at cryogenic temperatures. After resonant laser excitation of the captured atoms, the emitted fluorescence light is optically imaged onto a CCD camera, and the product atoms are counted individually. A Prototype Single Atom Microscope has been assembled, and we have developed a semi-automated film growth procedure for depositing 100 micron thick solid noble gas films of high optical quality. Film uniformity, and long term white light transmission have been studied for various film deposition and maintenance temperatures. |
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S01.00067: Raspberry Pi for Drift-gas System Readout Taylor Yeboah Slow controls read-out is highly valuable for nuclear physics experiments in that it ensures vital instrumentation data is obtained and archived. Raspberry Pi's serve as cost-effective, energy-efficient computers that can run a light-weight Linux operating system to utilize the necessary software for communicating with devices. Information such as temperature and pressure for detector gas systems are essential for recording. This study began with tests on a Raspberry Pi HAT sensor and the subsequent capability is now being applied towards development of read-out for the gas system for the BOund Nucleon Structure 12 (BONuS12) central detector. This presentation will detail the initial work done at Virginia Union University, current status and plans, as well as also show what great work dedicated students from various backgrounds can do |
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S01.00068: Neutron Energy Spectrum Distributions Surrounding an AmBe Source and a Medical Linear Accelerator John J Thomas, Jackson C Nolan, Erick W Bergstrom, Molly R McDonough, Brian Hassett, Dylan Barbagallo, Dr. Walter Johnson In a collaboration between Suffolk University and Massachusetts General Hospital, we have used multiple detection methods to determine the neutron energy spectrum of both an AmBe source and a 15 MV medical linear accelerator (LINAC). These detection methods include: high purity metal foil activation, bubble neutron detectors, and organic liquid scintillation. These methods allowed us to study the neutron energy spectrum distribution of each source. The high purity metal foils were layered to allow for localized energy neutron capture in both the thermal and epithermal regions of 0.025 eV to 250 keV. The neutron bubble detectors were used to provide evidence of a 1/r^2 distribution as well as the neutron fluence in the region of 250 keV to 15 MeV. The organic liquid scintillator was used to determine the neutron flux as well as the energy distribution in the region of 200 keV to 15 MeV. |
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S01.00069: A new CLAS12 experiment to study exclusive Short Range Correlations in Nuclei Holly Szumila-Vance This talk will discuss a newly approved experiment to systematically study nucleon-nucleon (NN) pairs in short- ranged correlations (SRC) that will run using the CLAS12 spectrometer at Jefferson Lab. SRC NN pairs account for about 20% of all nucleons in medium to heavy nuclei and about 75% of the nuclear kinetic energy. There is evidence linking these pairs to nucleon structure modification in nuclei (the EMC effect). By measuring high-statistics one-, two- and three-nucleon knockout reactions over a wide range of targets, this experiment will address some of the many open questions in SRC studies such as the existence and properties of Three-Nucleon SRCs (3N-SRCs), the nature of the NN interaction at short distances, how SRC pairs form, and the effect of SRC pairing on nucleon structure (the EMC effect). Improved statistics in conjunction with the use of varying beam energies and the CLAS12 wide acceptance provide an increased kinematical coverage, allowing for a 3N-SRC search in exclusive reactions, detailed studies of momentum transfer and kinematical dependencies, as well as mass number (A) and nuclear symmetry (N = Z) dependencies of SRCs. This talk will present the physics goals of the experiment and provide an overview of the run plan. |
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S01.00070: Development of tracking detectors for FRIB Yassid Ayyad, Marco Cortesi The next-generation Facility for Rare Isotope Beams (FRIB) will provide unprecedented intensities for the most exotic beams available anywhere. FRIB will enable scientists to explore the uncharted region of the nuclear landscape to provide answers to fundamental questions about nuclear structure, fundamental symmetries and forces , and nucleosynthesis of the elements. Such high intensities also bring unquestionable technical challenges: present radiation detector technologies will become obsolete as FRIB proceeds to its full power stage. Tracking detectors capable of withstanding FRIB intensities while providing high position, timing and energy resolutions are needed for almost every experiment and experimental setup. The NSCL/FRIB Detector Lab is striving to develop new concepts on radiation detectors to fulfill the needs of FRIB. In particular, a large effort is being made in the field of gaseous detectors based on parallel plate chambers (PPAC) and micro pattern gas detectors (MPGD). In this talk I will discuss the recent advances in the development of tracking detector for NSCL and for the future FRIB. |
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S01.00071: The Active Target Time Projection Chamber (AT-TPC) Yassid Ayyad The Active Target Time Projection Chamber (AT-TPC) at the NSCL-MSU is a novel active target detector tailored for low-energy nuclear reactions in inverse kinematics with exotic nuclei. The AT-TPC allows for a total 3D reconstruction of the reaction and provides high luminosity. The broad physics program of the AT-TPC covers many different fundamental questions in low-energy nuclear physics. The AT-TPC is currently installed in the ReA3 reaccelerated beam line at the NSCL. This beam line provides exotic beams at low energies very well adapted for the physics program of the AT-TPC. The AT-TPC can be operated under a magnetic field that enhances the identification of the particles while improving the resolution through the measurement of the magnetic rigidity. For fast beams, the current AT-TPC will feature a pad plane with an exit hole that will allow us to couple the detector to other apparatus, like the S800 spectrograph at the NSCL. Such detection scheme will greatly benefit from systems like SOLARIS featuring a solenoid magnet for studies with fast beams. Recent results and the future experimental program of the ATTPC will be discussed in this talk. |
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S01.00072: PHYSICS OF BEAMS
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S01.00073: Solvent and Concentration Effects Governing the Hierarchical Organization of Asphaltenes: A Small-Angle X-Ray Scattering Study Hasan R Rahman, Jose L Banuelos Asphaltenes are a group of planar molecules found in crude oil and are prone to aggregation which causes blockage of pipes along the oil production stream. The solution-state nanostructure of various asphaltene solutions was studied using small-angle x-ray scattering (SAXS) (over a Q-range of 0.008 - 0.4 Å-1) in order to understand solvent and concentration effects on asphaltene hierarchical organization. The fractal aggregate structure of asphaltenes was characterized as a function of concentration in toluene (1-50 mg/ml), tetrahydrofuran (1-500 mg/ml), and benzene (1-100 mg/ml). In toluene, the varying cutoff length, primary radius parameters, and the growing mass fractal dimension, all suggest that at a certain chain length, asphaltene nano-aggregates (NA) begin to collapse onto themselves to form a larger and denser aggregate. The experimental data has also been fit with several models including the Unified Power Law and the Ellipsoidal/Spherical Hayter Mean Spherical Approximation models to compare their characteristic parameters such as the ‘Guinier Radius’ and ‘Porod Slope’ to develop a consistent view of the hierarchical structure of asphaltene which will aid as a valuable input to develop strategies to mitigate the effects of asphaltene aggregation. |
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S01.00074: The Accelerator Tracking Code Zgoubi: Improving Performance, Features, and Graphical Interface Dan T Abell, Paul Moeller, Mike Keilman, Rob Nagler, Boaz Nash, Ilya V Pogorelov, Francois Meot, Izaak B Beekman, Damian W. I. Rouson The particle tracking code Zgoubi* has been used for a broad array of accelerator design studies, including FFAGs and electron-ion colliders. Zgoubi is currently being used to evaluate the spin polarization performance of proposed designs for both JLEIC ** and eRHIC ***, and to prepare for commissioning the CBETA BNL-Cornell FFAG return loop ERL ****. We describe our on-going work on several fronts, including efforts to parallelize Zgoubi using new features of Fortran 2018 *****, and a new implementation of Zgoubi's particle update algorithm. We also describe a new, web-based graphical interface for Zgoubi. * F. Méot, FERMILAB-TM-2010, 1997 |
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S01.00075: PRECISION TESTS OF PHYSICS LAWS
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S01.00076: Experimental Detection of Non-local Correlations using Navascues-Pironio-AcınHierarchy in the Tripartite States Amandeep Singh, Kavita Dorai, Arvind Arvind It has been shown, by Navascues et al, that fewer body correlations can reveal the non-local |
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S01.00077: Proton beam electromagnetic interactions with an RF cavity - analysis of wakefields Andrey V Semichaevsky Electromagnetic interactions of proton beams with RF cavities, also known as 'wakefields', affect dynamics of each particle and the collective beam dynamics [1]. Analytical techniques that are useful for computing wakefields in beampipes [2] are not applicable to resonant structures. Using FDTD calculations, time-varying electromagnetic fields induced by a single moving proton bunch are obtained. A numerical Green’s function approach is proposed to account for the wakefields due to individual superparticles within a particle-in-a-box model. Further analysis of electromagnetic fields inside an RF cavity is done using their time-frequency representations. Preliminary analysis suggests that with the increase in the number of protons per bunch to the order of 1012, or more, the wakefields in cavities may significantly affect beam dynamics. References: [1] Chao A.W., Physics of collective beam instabilities in high energy accelerators, Wiley, N.Y., 1993, 384 pp. [2] Macridin, A., Spentzouris, P., Amundson J., “Impedances and wake functions for non-ultrarelativistic beams in circular chambers,” FERMILAB-PUB-12-518-CD, 1-14. |
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S01.00078: Multi-Channel Readout IC for Nuclear Physics Experiments Esko Olavi Mikkola, Phaneendra Kumar Bikkina, Jinghong Chen, Andrew Levy Alphacore is developing low-cost, single-chip multi-channel readout integrated circuits (ROICs) for nuclear physics experiments. The ICs meet the critical requirements for a high-performance, low-cost readout solution needed by several current and planned nuclear physics experiment facilities. Alphacore is producing three different types of versatile and low-cost detector readout IC solutions: 16-channel preamplifier/shaper IC; 16-channel ADC IC; and 16-channel combined IC with preamplifiers, shaping amplifiers, ADCs, zero suppression logic and serializer output I/O circuitry optimized for interfacing to a low-cost FPGA. To cover as many current needs as possible, Alphacore has designed and taped out two different types of preamplifiers: low noise charge sensitive amplifier (CSA) operates in the detector capacitance range of 0 - 50pF with noise level in the range of 350ENC (Cd = 1pF) to 840 ENC (Cd = 50pF), and current conveyor-based preamplifier that operates for detector capacitances from 0pF to 300pF (and beyond) with a flat noise level of ~1,500ENC. [AL1]Particle physics? |
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S01.00079: Picosecond Timing Measurement IC for Particle Physics Experiments Esko Olavi Mikkola, Phaneendra Kumar Bikkina, Jinghong Chen, Andrew Levy Alphacore is developing a low-cost, single-chip multi-channel detector readout digitizer ASIC for high energy physics (HEP) experiments. This ASIC meets the critical need existing in several existing or planned HEP experiments for a high-performance, low-cost readout solution with picosecond timing measurement capability. Several HEP experiments require accurate timing measurements and transient digitization at high sampling rates, equaling or exceeding 5 GSPS. Alphacore's versatile ROIC is a solution for detectors that have fast pulse rise times (200ps – 1ns). The novel architecture is “as digital as possible”, i.e., it takes advantage of the advanced digital circuit performance (higher data bandwidths and clock rates at lower power and smaller area) of the newest CMOS generations. Alphacore’s innovation is a low-power gigasample-range ADC that has both “continuous ADC” and “buffered waveform digitizer” functions.
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S01.00080: Study of Particle Acceleration in a Star Forming Region Kelly Malone, Binita Hona, Henrike Fleischhack Star forming regions (SFRs) have been postulated as possible sources of cosmic rays in our galaxy. One example of a gamma-ray source associated with an SFR is the Fermi-LAT cocoon, an extended region of gamma-ray emission detected by Fermi-LAT in the Cygnus X region and attributed to a cocoon of freshly accelerated cosmic rays (CRs). CRs in the cocoon could have originated in the OB2 association and been accelerated at the interaction sites of stellar winds of massive O type stars. Hence, in that case, the Fermi-LAT cocoon is a superbubble. So far, this cocoon has been only detected at GeV energies. The HAWC observatory has detected a TeV gamma-ray source 2HWC J2031+415 co-located with the cocoon. Spectral and morphological studies of the region with HAWC and Fermi-LAT data reveal the HAWC source as a likely counterpart of the cocoon. The spectral energy distribution of the cocoon extends from GeV to TeV. Using HAWC data, we are able to study the acceleration of particles to highest energies in the Cygnus OB2 SFR. |
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