Bulletin of the American Physical Society
APS April Meeting 2021
Volume 66, Number 5
Saturday–Tuesday, April 17–20, 2021; Virtual; Time Zone: Central Daylight Time, USA
Session SP01: Poster Session II (14:00 - 16:00 CT)Poster Undergrad Friendly
|
Hide Abstracts |
|
SP01.00001: ChaNGa N-body code and the AGORA CosmoRun paper J.W. Powell, Thomas Quinn, Santi Roca-Fabrega, Hector Velazquez AGORA is an acronym for Assembling Galaxies of Resolved Anatomy, and this project [J. Kim, et al. ApJ Supp., \textbf{210}, 14 (2014) ] is approximately twelve years old and continuing strong. The CosmoRun paper is the third in this series and is a comparative set of zoom-in cosmological simulations of five codes using the same initial conditions (described in the poster): two smooth particle hydrodynamics (SPH) codes and three adaptive mesh refinement (AMR) codes. The paper demonstrates that under the four calibrations -- described briefly below -- diverse computational approaches to this type of simulation can roughly converge. ChaNGa is not one of the codes in the paper despite many simulations and intense effort. The four calibrations increase in complexity of the simulations and at each step all five codes come to a convergence due to frequent zoom-like meetings. The first calibration does not use any cooling. The second calibration turns on cooling using the program GRACKLE [B.D. Smith, et al. MNRAS {\bf 466}, 2217 (2017)]. The third calibration turns on star formation. Finally, the fourth calibration turns on feedback. The selected results of each calibration will be presented. [Preview Abstract] |
|
SP01.00002: Quantum-Spacetime(QST) Empty/Black(E/B) Lemaitre-De Sitter(LD) Universe-Evolution(UE) Creep-Plasticity (CP) Time-Series(TS) Burst-Acoustic-Emission(BAE) Serrated-Yielding(SY)/ Portevin-LeChattlier-Effect(PLE) Transition to Visco-Elasicity/Plasticity(VEP) Edward Seigel, Frank Nabarro, Peter Feltham, Andrew Jonsher, James Eshelby, John Bilby, Rudolph Peierls, Alan Brailsford, Michael Ashby, Jacques Friedel, George Ansel, Anthony Arrott, Malcolm Hepwirth, Lloyd Motz, Fredric Young LD UE CP TS SY/PLE HT Kaiser-effect(KE) dominated BAE[aka “Silk/Shapiro/Tegmark” baryon-acoustic-oscillations(“BAO”)]-Siegel[MSE(71);APS Shocks Confs.:Chicago(05);...; (21)] shocks BAE SY/PLE transition to relatively-smooth CP [Siegel[CB BAE, PSS (71)-2 pprs;Intl.Conf.AE,Tokyo(76);Xl-Lattice-Defects(77);Intl.Conf.Internal-Friction/Ultra-sonic- Attenuation,UK(79);Aristotle Birthday Symp.Physics/Mechanics,Thessaloniki(90)]; and memoryful/hysteresis Bauschinger-effect/dynamic-plasticity-rebound-overshoot cyclicity[van Bueren[Imperfections/Crystals(61)-p240];[Singular-Perts./Hysteresis (05)];Siegel [IEEE Ultra- sonics Symp.(73);Acta Met.(77)]. Deep-connections exist to cosmogony/GR-FE LD-solutions as CP-UE[Pathria[G-R(74)-p277];M/T/W[Gravitation(73)-p.1207/8];Genz[Nothingness(99)]; Siegel[APS 4-Mtg.(20)]] E/B Minkowski fluctuating QST/“firmament”/“tohu”: “UE ‘as’/IS(!) CP Guth/inflation balloon”: UE VEP mechanics!/biology? [Preview Abstract] |
|
SP01.00003: Mapping the Spatial Extent of Star Formation in Filamentary Structures Chanuntorn Pumpo, Vanessa Havens, Nancy Asante, Rose Finn We are conducting a multi-wavelength study of the gas in galaxies at a variety of positions in the cosmic web surrounding the Virgo cluster, one of the best studied regions of high density in the Universe. Galaxies are very likely pre-processed in filaments before falling into clusters, and our goal is to understand how galaxies are altered as they move through the cosmic web and enter the densest regions. In this poster, we present resolved H-alpha imaging for galaxies in the NGC5353 filament, which runs tangentially behind the Virgo Cluster. The H-alpha imaging data were taken with the KPNO 0.9-m telescope on Kitt Peak, and the goal is to measure the spatial distribution of star formation and compare with the distribution of the stellar disk. We will combine the star-formation maps with observations of molecular and atomic gas to calculate gas consumption timescales, characterize multiple phases of the galactic gas, and look for signatures of environmentally-driven depletion. [Preview Abstract] |
|
SP01.00004: Rate Change Science Origins: Center of the Universe Kenneth Strickland A re-organization and modernization for rate of change brings into focus a location for the center of the universe. Information needed to understand the physics is already known. RCS concentrates on building a universe rather than reverse engineering the milestone moments of time. RCS sees the big bang too but unfurls through the building of ``Default Matter Objects''. The analysis reveals a wealth of knowledge including the geometrical center object and the physical center object in our universe. At the heart of the center object is dark matter. [Preview Abstract] |
|
SP01.00005: Could ``ROC'' Support My Hypothesis of The Dark Matter Ring Dayong Cao A new observation of ``odd radio circles" has a structure which likes my hypothesis of the ring structure of the dark matter. he dark matter is a spacetime (backgroundwave) which has close-ring structureand center structure, a density of the spacetime (spacetime/massenergy), and a negative gravit. And the spacetime field can cause the Hubble's Red Shift. If the``ROCs'' are some high density structures of the spacetime (field) which can Redshift the high frequency radiations to low frequency radio waves, ``ROCs''can be observed by the radio telescope. See Ray Norris, ``'WTF?': Astronomers are baffled by a new ghostly phenomenon in space''. \underline {https://www.alternet.org/2020/12/astronomy-mysteries/} \subsubsection{See Dayong Cao, ``Ring Structure of Center of Spacetime, DNA, and Extraterrestrial Being'' , and ``New Einstein Field Equation Explains of Dark Matter and Dark Energy''.} \label{subsubsec:mylabel1} \underline {http://meetings.aps.org/Meeting/MAR16/Session/F33.11} http://meetings.aps.org/Meeting/APR18/Session/Y13.2 \underline {NASA Warn To Supports My Hypothesis (2011) Which Asteroids Will Impact Our Earth in 2030}? [Preview Abstract] |
|
SP01.00006: Charon: A New Neutrino Generator for WIMP Dark Matter Qinrui Liu, Jeffrey Lazar, Carlos Argüelles, Ali Kheirandish Indirect searches for signatures of corpuscular dark matter have been performed using all cosmic messengers: gamma rays, cosmic rays, and neutrinos. The search for dark matter with neutrinos is of particular importance since they are the only courier that can reach detectors from dark matter processes in dense environments, such as the core of the Sun or Earth, or the edge of the observable Universe. One thing essential to experiments is the prediction of the neutrino signature at the detector. In this talk, I will introduce χaroν, a software that bridges the dark sector and Standard Model by predicting neutrino fluxes from different celestial dark matter agglomerations. This package includes neutrino production coupled to a new calculation of electroweak corrections and neutrino propagation to the observer's location. [Preview Abstract] |
|
SP01.00007: Dark matter may be holes, and that may be seen from the Commutator in Quantum Mechanics Richard Kriske The Commutator in Quantum Mechanics [Preview Abstract] |
|
SP01.00008: Search for dark matter in events with a Higgs boson decaying to two photons and missing transverse momentum in pp collisions at √s = 13 TeV with the ATLAS detector Jinfei Wu, Yanping Huang, Xinchou Lou A dark matter search in the events with a Higgs boson decaying to two photons and missing transverse momentum is performed. The $139~\mathrm{fb}^{-1}$ of proton-proton collision data collected at the centre-of-mass energy of 13 TeV with the ATLAS detector at the CERN LHC between the years 2015 and 2018 is used in this study. The results are interpreted in a simplified model with a massive vector mediator that emits a Higgs boson and subsequently decays into a pair of dark matter candidates, and in a two-Higgs-doublet model with either a vector or a pseudoscalar mediator to a pair of dark matter candidates. No significant excess beyond the Standard Model is observed. [Preview Abstract] |
|
SP01.00009: Scale-Invariant Dynamics of Galaxies, MOND, Dark Matter, and the Dwarf Spheroidals Vesselin Gueorguiev, Andre Maeder The Scale-Invariant Vacuum (SIV) theory is based on Weyl's Integrable Geometry. The main difference between MOND and the SIV theory is that the first considers a global dilatation invariance of space and time, where the scale factor $\lambda$ is a constant, while the second opens the likely possibility that $\lambda$ is a function of time. The key equations of the SIV framework are used here to study the relationship between the Newtonian gravitational acceleration due to baryonic matter $g_{\rm bar}$ and the observed kinematical acceleration $g_{\rm obs}$. The relationship is applied to galactic systems of the same age where the Radial Acceleration Relation (RAR), between the $g_{\rm obs}$ and $g_{\rm bar}$ accelerations, can be compared with observational data. The SIV theory shows an excellent agreement with observations and with MOND for baryonic gravities $g_{\rm bar}>10^{-11.5}$ m s$^{-2}$. Below this value, SIV still fully agrees with the observations, as well as with the horizontal asymptote of the RAR for dwarf spheroidals, while this is not the case for MOND. These results support the view that there is no need for dark matter and that the RAR and related dynamical properties of galaxies can be interpreted by a modification of gravitation. [MNRAS{\bf 492}, 2698(2020)]. [Preview Abstract] |
|
SP01.00010: Accurately Measuring Neutrinos and Massive Light Relics Using Cosmological Observables Nicholas DePorzio, Weishuang Xu, Julian Muñoz, Cora Dvorkin Light relics are new degrees of freedom which decoupled from the Standard Model while relativistic. Nearly massless relics will both contribute to the radiation energy budget and, for relics with masses on the eV scale (meV-10 eV), will become non-relativistic before today, behaving as matter instead of radiation. Such relics leave an imprint in the large-scale structure of the universe as light relics have important streaming motions, as in the case of massive neutrinos. For massive neutrinos, in order to obtain unbiased estimates of the neutrino mass, the sensitivity of upcoming CMB and LSS surveys to two effects that can alter neutrino-mass measurements is explored. The first is the slight difference in the suppression of matter fluctuations that each neutrino-mass hierarchy generates at fixed total mass. The second is the growth-induced scale-dependent bias (GISDB) of haloes produced by massive neutrinos. Accounting for these effects, a forecast of how well current and upcoming cosmological surveys can probe generic light massive relics is discussed. This forecast considers minimal extensions to the Standard Model by both fermionic and bosonic relic degrees of freedom and predicts the significance at which relics with different masses and temperatures can be detected. [Preview Abstract] |
|
SP01.00011: The ORGAN Experiment: Phase 1a Status and Results Aaron Quiskamp, Michael Tobar, Ben McAllister We present experimental details and initial results for Phase 1a of the Oscillating Resonant Group AxioN (ORGAN) Experiment, a microwave cavity axion haloscope interested in exploring the highly motivated $\sim60-200~\mu$-eV region of axion mass parameter space, corresponding to 15 - 50 GHz photons. Phase 1a employs a TM$_{010}$ based tuning-rod resonator to place the strongest limits to date in the 15+ GHz mass region of the axion-photon coupling parameter space, and serves as a test of the ALP co-genesis model. Prior to cavity fabrication, extensive finite-element modelling was completed to optimise resonator dependent parameters based on the $C^2V^2G$ figure of merit (a product of the form factor, volume and geometry factor) in the targeted 15 - 16 GHz frequency range. This initial phase of ORGAN operates at 4K in a 12 T magnetic field, and uses readily available low noise HEMT-based amplifiers. Whilst this experiment is capable of placing sensitive limits on axion-photon coupling in its own right, it also serves as a path-finder for future ORGAN runs. Subsequent stages of ORGAN will utilise the Phase 1a infrastructure as a test bed for various technologies and techniques, such as GHz single photon counting, and novel cavity designs, to explore the full 15-50 GHz range. [Preview Abstract] |
|
SP01.00012: Cosmic Interactions and dark matter Replace this text with your abstract title. Suresh Ahuja Several phenomenological approaches and ad-hoc assumptions have been attempted for description of experimental characteristics there and for getting reliable physical conclusions. Antideuteron and antihelium nuclei have been proposed as promising detection channels for dark matter because of the low astrophysical backgrounds expected. Scattered DM flux by cosmic-ray protons, and the resulting emission of secondary -rays and high-energy neutrinos from proton excitation, hadronization, and the subsequent meson decay has been analysed. An energy-dependent coalescence mechanism developed previously was extended to estimate the production of light antinuclei. The uncertainty in the coalescence parameter and its effect on the expected antiparticle flux present is given.. Direct search for interactions of antimatter with dark matter under direct constraints can result in interaction of ultralight axion-like particles (dark-matter candidates) with antiprotons. If antiprotons have a stronger coupling to these particles than protons do, such a matter--antimatter~asymmetric coupling could provide a link between dark matter and the baryon asymmetry in the Universe. To estimate both potential exotic contributions and their backgrounds, one usually employs the coalescence model in momentum space. In a recent developed coalescence model based on the Wigner function representations of the produced nuclei states. Tthe model describes the production of various antinuclei both in electron-positron annihilation and in proton-proton collisions. Replace this text with your abstract body. [Preview Abstract] |
|
SP01.00013: Strangeness-neutral Equation of State for QCD with a Critical Point Damien Price, Angel Nava, Jamie Stafford, Claudi Ratti, Debora Mroczek, Jacquelyn Noronha-Hostler, Paolo Parotto Our group presents a family of strangeness-neutral equations of state (EoS) for QCD. This family exhibits correct critical behavior, matches results on Taylor expansion coefficients from Lattice QCD, is compatible with the SMASH hadronic transport approach, and fits in temperature and chemical potential ranges relevant to the Second Beam Energy Scan (BESII)at RHIC. With strangeness-neutrality conditions in mind the BES-EoS software that produces the EoS has been updated. This makes the BES-EoS more accurately reproduce the system in a heavy-ion collision, which is known to possess zero global strangeness density and a fixed ratio of electric charge to baryon number. By utilizing the behavior of a critical point in the 3D Ising model universality class, the code outputs thermodynamic quantities relating to the behavior involving the critical point in the QCD phase diagram. With this output in combination with data from the BESII we hope to help constrain the location of the critical point in the QCD phase diagram. We also present a comparison of the isentropic trajectories in a strangeness-neutral system as opposed to the previous version not including strangeness-neutrality. [Preview Abstract] |
|
SP01.00014: Monte-Carlo simulations of multi-specie relativistic thermalization for Big bang nucleosynthesis. Atul Kedia, Grant Mathews, Nishanth Sasankan, Motohiko Kusakabe Multi-component relativistic fluids have been studied for decades. However, simulating the dynamics of the particles and fluids in such a mixture has been a challenge due to the fact that such simulations are computationally expensive in three spatial dimensions. Here we report on the development and application of a multi-dimensional relativistic Monte-Carlo code of explore the thermalization process in a relativistic multi-component environment in a computationally inexpensive way. As an illustration we simulate the fully relativistic three-dimensional Brownian-motion-like solution to the thermalization of a high mass particle (proton) in a bath of relativistic low-mass particles (electrons). We follow the thermalization and ultimate equilibrium distribution of the Brownian-like particle as can happen in the cosmic plasma during big bang nucleosynthesis. We also simulate the thermalization of energetic particles injected into the plasma as can occur, for example, by the decay of massive unstable particles during the big bang. [Preview Abstract] |
|
SP01.00015: The Growth of the Density Fluctuations in the Scale-Invariant Theory Vesselin Gueorguiev, Andre Maeder In the standard model, for a matter dominated universe, the growth of the density perturbations evolves with redshift $z$ like $(\frac{1}{1+z})^s$ with $s=1$. This is not fast enough to form galaxies and to account for the observed present-day inhomogeneities. This problem is usually resolved by assuming that at the recombination epoch the baryons settle down in the potential well of the dark matter previously assembled during the radiation era of the universe. This view is challenged in the present paper by using the recently proposed model of a scale-invariant framework for cosmology.\\ \\ From the continuity, Euler, and Poisson equations written in the scale-invariant framework, the equation governing the growth of density fluctuations $\delta$ is obtained. Starting from $\delta = 10^{-5}$ at $z\approx1000$, numerical solutions for various density background are obtained. The growth of $\delta$ is much faster than in the standard EdS model. The $s$ are in the range from 2.7 to 3.9 for $\Omega_{\rm m}$ between 0.30 and 0.02. This enables the density fluctuations to enter the nonlinear regime with $\delta > 1$ long before the present time, typically at redshifts of about 10, without requiring the presence of dark matter. [Physics of the Dark Universe {\bf 25} (2019) 100315]. [Preview Abstract] |
|
SP01.00016: Improved Modeling of EMRI Signal Confusion Noise for LISA Daniel Oliver, Aaron Johnson, Ben Russell, Lena Janssen, Joel Berrier, Daniel Kennefick Scattering events around a supermassive black hole (SMBH) will occasionally toss a stellar-mass compact object (CO) into an orbit around the SMBH, beginning what is known as an extreme mass ratio inspiral (EMRI). The early stages of such a highly eccentric EMRI will not produce detectable gravitational waves because the source will only be in a suitable frequency band briefly (close to peribothron) during each long-period orbit. However, if we consider an ensemble of such subthreshold sources, spread across the Universe, together they produce an unresolvable background noise that may obscure sources otherwise detectable by LISA, the proposed space-based gravitational wave detector. Previous studies of this EMRI signal confusion background used a Newtonian order approximation. We seek to improve this characterization by implementing kludge waveforms from relativistic population models developed by a semi-relativistic code that can calculate highly eccentric orbits. Further, our group has used the Illustris cosmological simulation to improve on previous black hole mass functions. Here we present some of the preliminary results of this study. [Preview Abstract] |
|
SP01.00017: The Development and Testing of a Low-cost, High Definition Heterodyne Phase Camera Cole Perkins, Kaden Loring, Mauricio Diaz-Ortiz, Fritzgerald Duvigneaud, Fabian Magaña-Sandoval, Paul Fulda, Ryan Goetz Precision interferometry experiments like Advanced LIGO are increasingly limited by imperfections in the spatial properties of the interfering beams, especially with the advent of squeezed-light enhanced sensitivities. In order to correct these imperfections, it is first necessary to measure them. This is not a trivial task, because the transverse phase profile of a beam is just as important as the intensity in determining the spatial mode purity. We will present the methods of creating a Heterodyne Phase Camera (HPC) and describe its measured performance. The HPC maps the spatial wave front of two interfering laser beams by detecting the phase of the beat note as resolved by different pixels of a CMOS camera. These phase maps can be displayed real-time or processed offline for a more detailed analysis. By illuminating the entire CMOS sensor with two spatially homogenous beams the transverse phase error of the HPC was found to be 0.058 radians which corresponds to a precision of 9.8nm. We will show how the HPC can be used to characterize novel optical components such as electro-optic beam deflectors and electro-optic lenses. This work is supported by NSF PHY-1806461 [Preview Abstract] |
|
SP01.00018: IPTADR2 Analyses and Rapid, Incoherent PTA Dataset Combination Levi Schult, Stephen Taylor, Joe Simon, Sarah Vigeland The International Pulsar Timing Array (IPTA) is an international collaboration of astronomers working to time multiple pulsars to detect evidence of gravitational waves in their timing residuals. In 2019, the IPTA released Data Release 2 (IPTADR2) which consists of timing solutions and times of arrival for 65 pulsars across the sky. We worked to test new, fast ways to explore the data for evidence of gravitational waves using one pulsar in particular, J1713$+$0747. This pulsar was selected for its long timing baseline, timing precision, and unique advantage of being observed by all constituent PTAs. We will continue to test similar pulsars to further understand these techniques. We additionally conducted some other full array analyses, such as the Factorized Likelihood and Dropout approaches to explore signals in IPTADR2. We present these preliminary results here. [Preview Abstract] |
|
SP01.00019: Neutron Star Masses and GW190425 Marc Penuliar, Jocelyn Read In 2019, the gravitational wave observatories of LIGO and Virgo discovered a second neutron star binary, GW190425, with a high total mass of about 3.4 solar masses (M$\odot$). Notably, the mass of its heaviest component is estimated to lie between 1.61 M$\odot$ and 2.52 M$\odot$. This makes GW190425 unusual compared to galactic double neutron star binaries. While mass measurements of all galactic neutron stars show a range of values between roughly 1 and 2.5 times the mass of the sun, those in double neutron star binaries have components around 1.4 M$\odot$, and LIGO’s first neutron star merger observation, GW170817, was compatible with two components around 1.4 M$\odot$. Here, we compare the range of masses compatible with GW190425 to a neutron star binary population generated using the full galactic mass distribution. We use the double Gaussian distribution fit by Alsing et al 2018 for the galactic masses. Our comparison suggests that, if the new binary came from a population with masses as seen in our galaxy, GW190425 had a larger mass ratio than suggested by gravitational-wave data alone, with one component near the typical 1.4 M$\odot$ value and the other similar to the most massive neutron stars observed in our galaxy. [Preview Abstract] |
|
SP01.00020: Waveform Systematics of Compact Binary Coalescence Models Aasim Jan, Anjali Yelikar, Jacob Lange, Richard O'Shaughnessy As Einstein's equations for binary compact object inspiral have only been approximately or intermittently solved by analytic or numerical methods, the models used to infer parameters of gravitational wave (GW) sources are subject to waveform modeling uncertainty. We illustrate these differences, then introduce a very efficient technique to marginalize over waveform uncertainties, relative to a pre-specified sequence of waveform models. Being based on RIFT, a very efficient parameter inference engine, our technique can directly account for any available models, including very accurate but computationally costly wave- forms. Our evidence and likelihood-based method works robustly on a point-by-point basis, enabling accurate marginalization for models with strongly disjoint posteriors while simultaneously increasing the re-usability and efficiency of our intermediate calculations. [Preview Abstract] |
|
SP01.00021: Search for Black Hole Merger Families Doga Veske, Andrew Sullivan, Zsuzsa Marka, Imre Bartos, Kenneth Corley, Johan Samsing, Riccardo Buscicchio, Szabolcs Marka The origin, environment, and evolution of stellar-mass black hole binaries are still a mystery. One of the proposed binary formation mechanisms is manifest in dynamical interactions between multiple black holes. A resulting framework of these dynamical interactions is the so-called hierarchical triple merger scenario, which happens when three black holes become gravitationally bound, causing two successive black hole mergers to occur. In such successive mergers, the black holes involved are directly related to each other, and hence this channel can be directly tested from the properties of the detected binary black hole mergers. Here we present a search for hierarchical triple mergers among events within the GWTC-1 and GWTC-2 catalogs of LIGO/Virgo, the eccentric localization of GW190521 and those found by the IAS-Princeton group. We perform our analysis for different upper bounds on the mass distribution of first generation BHs. Our results demonstrate the importance of the mass distributions' properties for constraining the hierarchical merger scenario. We present the individually significant merger pairs. The search yields interesting candidate families and hints of its future impact. [Preview Abstract] |
|
SP01.00022: Studying Expansion of Ejecta from Binary Neutron Star Mergers Hyun Lim, Oleg Korobkin, Jonah Miller, Ryan Wollaeger, Christopher Fontes, Mark Alexander Kaltenborn, Wesley Even, Julien Loiseau Neutron star mergers provide an exciting opportunity to study physics at the extreme, such as strong gravity, nuclear equation of state, and r-process nucleosynthesis. One of the signature events associated with such mergers is a kilonova, first unambiguously discovered in the afterglow of the GW170817 merger event. Accurate modeling of kilonova requires an understanding of the ejecta morphology, which can play a significant role in determining its brightness and color. In this work, we explore the expansion of neutron star merger ejecta with the new LANL smoothed particle hydrodynamics code, FleCSPH, which is based on the FleCSI computational infrastructure. We follow simulations of accretion disk outflows [Miller et al. 2019] beyond the outer boundary of the original computational grid, using a Lagrangian particle method. We use a realistic, high density nuclear equation of state and nuclear heating from a nucleosynthesis network. The expanded ejecta morphology is then used as a background for radiative transport calculations with LANL opacities of lanthanides. Resulting spectra and light curves are presented. [Preview Abstract] |
|
SP01.00023: Electromagnetic precursor flares from neutron star mergers Elias Most, Alexander Philippov Gravitational wave events of merging neutron stars are exciting laboratories for multi-messenger astronomy, featuring gravitational wave emission as well as electromagnetic counterparts. Apart from the afterglow and short gamma-ray burst observed for GW170817, there is another potential electromagnetic counterpart that has not yet been detected. Because neutron stars are equipped with strong magnetic fields, the non-trivial interaction of two neutron star magnetospheres before the merger might give rise to an electromagnetic precursor emission.In this talk, I will present a mechanism for launching powerful electromagnetic flares during the inspiral of two neutron stars. Using special-relativistic force-free electrodynamics simulations, I will demonstrate that differential motion, such as relative spin differences between the neutron stars or misalignment of the magnetic field with the orbital axis, can naturally lead to a periodic emission of such flares. I will also comment on the viability to produce radio emission in this process. [Preview Abstract] |
|
SP01.00024: PIC simulations of Weibel instability and its spectral studies Michael Sitarz, Mikhail Medvedev, Alexander Philippov The Weibel instability is ubiquitous in astrophysical plasmas, which are present in collisionless shocks, early state of supernovae and gamma-ray bursts, and others. This instability generates strong magnetic fields from scratch. The generated electromagnetic fields reside on the plasma skin-depth scale, which is smaller than the effective Larmor scale. Radiation from such sub-Larmor-scale fields, known as the jitter radiation, markedly differs from the cyclotron or synchrotron radiation. Its spectrum carries wealth of information about the magnetic field properties. Here we present the spectral studies the Weibel instability with PIC simulations. The generation of high-frequency electromagnetic fluctuations is observed. The resultant spectrum, its temporal and angular distribution of the emitted power are discussed. [Preview Abstract] |
|
SP01.00025: CCSN Simulation with Spectral Two-Moment Neutrino Transport Using FLASH Ran Chu, Austin Harris, Eirik Endeve, Bronson Messer, Anthony Mezzacappa We are developing the toolkit for high-order neutrino-radiation hydrodynamics (thornado) to model neutrino transport in core-collapse supernova (CCSN) explosion simulations. thornado, which implements spectral two-moment neutrino transport using the discontinuous Galerkin method and implicit-explicit time stepping\footnote{\tiny Chu et al. 2019, JCP, {389}, 62; Laiu et al. 2020, J. Phys.: Conf. Ser. 1623, 012013; Laiu et al. 2020, ApJS (submitted)}, as well as WeakLib\footnote{\tiny github.com/starkiller-astro/weaklib}, a library providing tabulated microphysics, has been coupled with FLASH\footnote{\tiny Fryxell et al. 2000, ApJS, 131, 273} as an external library. With this enhanced FLASH code, we aim to simulate CCSN explosions in multiple spatial dimensions. Here we present (1) a detailed comparison between Boltztran\footnote{\tiny Mezzacappa and Bruenn 1993, ApJ, 405, 669} and thornado in the context of a fixed, spherically symmetric, post-bounce profile from a simulation that used the LS220 equation of state (EoS) and ``Bruenn~85'' neutrino opacities, and (2) the spherically symmetric gravitational collapse of a 15 solar mass progenitor using the SFHo EoS, Bruenn~85 opacities, FLASH's Newtonian hydrodynamics with self-gravity, and thornado's neutrino transport. [Preview Abstract] |
|
SP01.00026: thornado-Hydro: A Discontinuous Galerkin Method for General Relativistic Hydrodynamics with an Eye towards Simulating Core-Collapse Supernovae Samuel Dunham, Nick Roberts, Zachary M. Elledge, Eirik Endeve, Anthony Mezzacappa, Kelly Holley-Bockelmann, David Pochik, Brandon Barker, Jesse Buffaloe We present results from thornado [1], a neutrino-hydrodynamics code being developed for simulations of core-collapse supernovae that uses high-order-accurate discontinuous Galerkin (DG) methods [2]. Here, our primary focus is on the module that solves the hydrodynamics equations under the conformally-flat approximation (CFA) to general relativity (GR) [3], and its coupling to Poseidon [4], a CFA gravity solver. GR is needed to capture properly, among other things, the compactness of the proto-neutron star and, in turn, the neutrino luminosities emanating from it (e.g., see [5]). We discuss details of the numerical method and show results from the self-similar collapse of a polytropic star, as well as the adiabatic collapse of a 15 solar mass progenitor. The latter requires a tabulated, nuclear equation of state to capture the dynamics up to bounce. The results from each of these test problems are compared with their Newtonian counterparts [6]. We also discuss progress on our work to develop a DG neutrino transport solver under the CFA. [1] Dunham et al. 2020 J. Phys.: Conf. Ser. 1623 012012 [2] Cockburn \& Shu 2001 JSC 16 173 [3] Wilson et al. 1996 PRD 54 1317 [4] Roberts et al. 2021 (in prep.) [5] Bruenn et al. 2001 ApJ 560 326 [6] Pochik et al. 2020 arXiv: 2011.04680 [Preview Abstract] |
|
SP01.00027: Multiband Detection of Repeating FRB 20180916B Jakob Faber, Ketan Sand, Vishal Gajjar, Daniele Michilli, Bridget Andersen We report a series of joint detections of FRB 20180916B, a source that has been discovered to exhibit a 16.35-day periodicity with a ~4-day active phase window, between the GBT (600-1000 MHz), uGMRT (300-500 MHz), and CHIME (400-800 MHz) radio observatories. We observed a total of 7, 4, and 1 bursts respectively, which spanned the collective 700 MHz bandwidth over the course of ~3 days. The GBT detections were made earlier in the active phase window and exhibited a significantly higher burst-rate compared to uGMRT. In both GBT and uGMRT detections, we observe clear downward-drifting emissions and narrow multi-component time-frequency modulations that motivate the use of baseband data to investigate FRB sub-structure. We discuss how such features might be leveraged in disentangling effects intrinsic to the emission mechanism from those superimposed the surrounding medium during propagation. The analysis was performed using the transient detection pipeline SPANDAK and analysis pipeline FLITS, which currently run on the Breakthrough Listen backend at the GBT. [Preview Abstract] |
|
SP01.00028: Thornado-hydro: A Discontinous Galerkin Method for Supernova Hydrodynamics with Nuclear Equations of State David Pochik, Brandon Barker, Eirik Endeve, Jesse Buffaloe, Samuel Dunham, Nick Roberts, Anthony Mezzacappa We present hydrodynamics results from the toolkit for high-order neutrino radiation hydrodynamics (thornado), which is being developed for multiphysics simulations of core-collapse supernovae (CCSNe), and related problems, with Runge-Kutta discontinuous Galerkin (RKDG) methods [1]. Our method includes extensions -- a slope limiter to prevent non-physical oscillations and a bound-enforcing limiter to prevent non-physical states -- to the standard RKDG framework, to accommodate a tabulated nuclear equation of state (EoS). The numerical results from test problems in idealized settings demonstrate the efficacy of the extended method. Taking important steps toward full CCSN simulations with thornado, our method is then applied to the problem of adiabatic collapse, shock formation, and shock propagation in spherical symmetry, initiated with a 15 Solar mass progenitor. In this application, the bound-enforcing limiter improves robustness of the RKDG method, but slope limiting in characteristic fields is vulnerable to phase transitions in the EoS. We also include preliminary work of coupling this method with two-moment neutrino transport. [1] Pochik et al. 2021, ApJS (accepted, arXiv:2011.04680) [Preview Abstract] |
|
SP01.00029: The geometry of SMC X-2 from Polestar Ankur Roy, Rigel Cappallo, Georgios Vasilopoulos, Sayantan Bhattacharya, Silas Laycock, Dimitris Christodoulou SMC X-2 is one of the brightest pulsars in the Small Magellanic Cloud (SMC).This transient Be/X-ray pulsar with a spin period of P$_{spin}$ = 2:37 s and an orbital period of P$_{orb}$ = 18.62$\pm$0.02 days last underwent a Type-II outburst in 2015. Following its detection by MAXI, simultaneous observations were carried out by Swift, XMM-Newton, and NuSTAR throughout the outburst phase extending for up to two months. The source is one of few SMC pulsars in which the propeller state was observed and a cyclotron resonance feature was detected at E $\sim$ 27 keV. The onset of the propeller regime causes dramatic changes in the accretion state and the neutron-star magnetosphere. This serves as impetus for trying to model the observed pulse profiles in various accretion states in order to deduce the geometry of the emitting regions. For this analysis, we use the geometrical pulse-profile modeling code Polestar. This modeling effort will help us pinpoint the geometry of the emission and understand the energy and accretion changes as the source evolves past outburst and toward lower luminosity states. [Preview Abstract] |
|
SP01.00030: Pulsar Candidate Classification with Ensemble Methods and Optimized Dimensionality Reduction Lucas Lima As the volume of pulsar candidate data continues to rapidly increase, filtering for pulsar signals becomes increasingly challenging with existing methods. Detection of pulsars is made inefficient because of the need for manual filtering of candidate signals, and this hinders the potential for collecting larger amounts of pulsar data. This research investigates low-cost methods of automating and optimizing this process of detecting pulsars between given candidates using ensemble machine learning algorithms and dimensionality reduction. Using labeled data published from the HTRU 1 and HTRU 2 surveys, classification models were trained after analyzing and processing the data and then implementing bagging and boosting algorithms. The models were optimized by using a brute-force algorithm that would evaluate the statistical features’ effects on the models’ predictive capabilities and remove those that were most detrimental. This would effectively reduce the dimension-size for the learning algorithms and increase overall robustness. The results demonstrate the ability to process almost 2 million candidates every second. In addition, one of the models experimented on HTRU 1 achieved a precision rate of 0.99 and a recall rate of 0.97, outperforming many other existing classifiers. [Preview Abstract] |
|
SP01.00031: The Influence of HII Regions on DM Variations for PSRs J1614-2230 and J1643-1224 Samantha Rosenfeld, Shami Chatterjee, James Cordes, Stella Ocker Pulsar dispersion measure (DM) quantifies the integrated electron column density along the line of sight. Electron density fluctuations produce DM variations that induce errors in high precision pulsar timing used by the Nanohertz Observatory for Gravitational Waves (NANOGrav). We analyze DM variations of two pulsars observed by NANOGrav, PSRs J1614-2230 and J1643-1224, to determine if the HII regions along their LOS enhance their DM variations. Both pulsars exhibit linear changes in DM that are due to the transverse motions of the LOS through density gradients in the interstellar medium (ISM). We calculate the motion of the pulsars' LOS through the HII regions and determine that the observed DM variations could trace density fluctuations on scales of astronomical units (AU) or less within the HII regions. J1614-2230 exhibits DM variations dominated by the solar wind, but both pulsars show additional periodic DM variations that are out of phase with the expected solar wind-induced fluctuations. These periodic DM variations are too large to be explained by the LOS motion through the HII regions, but could be induced by another local plasma structure that obstructs the LOS to both pulsars. [Preview Abstract] |
|
SP01.00032: On plasma modes in a strong-field plasma in magnetars Mikhail Medvedev Magnetars -- the strongly magnetized neutron stars -- have the surface field stronger than the Schwinger field. In such an environment, Maxwell's equations become nonlinear due to QED effects. Magnetar magnetospheres also contain substantial amounts of plasma. Thus, there is great interest in understanding how plasma modes are modified in a super-strong field. Here we derive the general equations describing QED plasma linear modes. We discuss the properties of the low-frequency modes, for which the transitions between the Landau levels can be safely neglected. The results can be important for understanding of propagation of radio and other low-frequency waves in a magnetar magnetosphere and, perhaps, for unraveling the origin of fast radio bursts. [Preview Abstract] |
|
SP01.00033: Cosmic, galactic, and geomagnetic fields sharply limit electron cosmic ray energies Franklin Felber Classical Lienard radiation in the cosmic microwave background limits the energy of cosmic ray electrons and positrons (CREs) detected at Earth to about 1 PeV. Galactic magnetic fields deplete the flux of high-energy CREs anisotropically from the direction of the Milky Way center. A method is presented for adjusting the CRE spectrum above a few TeV to account for the geomagnetic field. [Preview Abstract] |
|
SP01.00034: Prototype Development for an Air Cherenkov Array at the South Pole Matthias Plum, Anna AbadSantos, Antonio Banda, Aine Grady, Sean McLaughlin, Larissa Paul, Karen Andeen IceAct is a proposed array of small and cost effective Imaging Air Cherenkov Telescopes situated at the IceCube Observatory at the South Pole. Since January 2019, two prototype IceAct telescopes have been taking data during the South Pole winters. Two years of data-taking experience has taught us much about how these telescopes perform in the harsh South Pole environment. Here we will detail the lessons-learned and ongoing research and development efforts to update these prototypes for future Polar seasons. [Preview Abstract] |
|
SP01.00035: Probing Kaon-Decay-at-Rest (KDAR) in the Sun with the Deep Underground Neutrino Experiment (DUNE) Olexiy Dvornikov The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core of the Sun would provide a unique signature of dark matter annihilation. Since excellent angle and energy reconstruction are necessary to detect this monoenergetic, directional neutrino flux, DUNE with its vast volume and reconstruction capabilities, is a promising candidate for a KDAR neutrino search. In this talk, we will present a preliminary study in which we evaluate the proposed KDAR neutrino search strategies by realistically modeling both neutrino-nucleus interactions and the response of DUNE. Although reconstruction of the neutrino energy and direction is difficult with current techniques in the relevant energy range, the superb energy resolution, angular resolution, and particle identification offered by DUNE can still permit great signal/background discrimination. Moreover, there are non-standard scenarios in which searches at DUNE for KDAR in the Sun can probe dark matter interactions. [Preview Abstract] |
|
SP01.00036: Search for low energy neutrino counterparts to Gravitational waves with IceCube DeepCore Aswathi Balagopal V., Raamis Hussain, Michael Larson, Alex Pizzuto, Justin Vandenbroucke The IceCube Neutrino Observatory has conducted searches for transient astrophysical sources of neutrinos in the TeV energy range. Additional events may be observable by IceCube at lower energies, although the existing analysis rapidly loses sensitivity below about 1 TeV. The densely instrumented DeepCore sub-array provides the ability to reduce the threshold for observation from 1 TeV down to approximately 10 GeV. An event selection optimized for this purpose may be used for analyses that look for neutrino sources coincident in time and direction with transient sources. An overview of this will be presented, along with special focus on a follow up of gravitational wave transients published by the LIGO-Virgo collaboration, using this low-energy data selection. [Preview Abstract] |
|
SP01.00037: Towards Precision Pointing with a Mountaintop Radio Neutrino Detector Zachary Curtis-Ginsberg, Nicholas Gerace, Daniel Southall The Beamforming Elevated Array for COsmic Neutrinos (BEACON) searches for radio emissions from upgoing tau leptons produced by tau neutrino interactions in the Earth using a compact antenna array on a high elevation mountain. Calibrating the exact antenna positions on the rough mountainside terrain is a difficult but important challenge for array pointing performance. Sending pulsed radio signals from known locations is a commonly used technique for calibrating antenna positions; however, the steep incline and high elevation of the mountain makes it challenging to calibrate from a wide range of angles. Recent analyses have used anthropogenic signals from known radio transmitters, airplanes, and other common background sources, as a means for further calibration - yielding a larger catalog of pairs of signals and directions than pulsing from the ground could practically provide. Future plans include the use of a GPS-capable quadcopter drone pulser, which will allow for precise and efficient pulsing from a variety of source directions both above and below the horizon. In this poster, we discuss several calibration techniques used in BEACON and the achieved angular resolution with the prototype array. [Preview Abstract] |
|
SP01.00038: CALET Observations of the Quiescent Sun in GeV-energy Gamma Rays Nicholas Cannady Cosmic-ray interactions with the Sun and its radiation field give rise to a secondary gamma-ray signal. The first component of this emission is spatially confined to the Solar disk, coming from nuclear interaction of cosmic-ray protons with the Solar atmosphere. The second, spatially-extended component comes from inverse Compton scattering of the Solar radiation field by high-energy cosmic-ray electrons. These two components have been previously detected by the EGRET instrument on CGRO and the LAT instrument on the Fermi Gamma-ray Space Telescope. Recent results using Fermi-LAT data reveal intriguing features about the disk emission component, including dependence of the flux on the Solar cycle, emission to more than 100 GeV at Solar minimum, and the presence of an unexplained spectral dip at 30---50 GeV. In this study, we report on an independent measurement of the GeV-energy gamma-ray emission with the CALET instrument onboard the International Space Station, seeking particularly to independently validate the time-dependence of the flux and the presence of the spectral dip. [Preview Abstract] |
|
SP01.00039: Determination of Expected TIGERISS Observations Brian Rauch, Nathan Walsh, Wolfgang Zober We present the method used to estimate the cosmic-ray observations expected for that the Trans-Iron Galactic Element Recorder for the International Space Station (TIGERISS), which is designed to measure the abundances of the rare Ultra-Heavy Galactic Cosmic Rays (UHCR) $_{30}$Zn and heavier. TIGERISS uses planes of crossed silicon strip detectors at the top and bottom for charge and trajectory determination and acrylic and aerogel Cherenkov detectors for velocity and charge determination. Instruments are modeled for the Japanese Experiment Module (JEM) "Kibo" Exposed Facility ($\sim$1.66 m$^{2}$ sr), as an European Space Agency Columbus Laboratory external payload ($\sim$1.16 m$^{2}$ sr), and as an ExPRESS Logistics Carrier (ELC) experiment ($\sim$1.10 m$^{2}$ sr). Differential geometry factors determined for detector orientations within the geomagnetic field over the 51.6$^{\circ}$ inclination orbit are used to determine geomagnetic screening. Energy spectra are integrated using the higher of the energies needed to trigger the instrument or penetrate the geomagnetic field for time-weighted bins of geomagnetic latitude, instrument orientation, and incidence angle. Finally, abundances are reduced by the fraction of events calculated to fragment in the instrument. [Preview Abstract] |
|
SP01.00040: NUCLEAR PHYSICS |
|
SP01.00041: Fast Neutrino Cooling of Nuclear Pasta in Neutron Stars: Molecular Dynamics Simulations Zidu Lin, Matthew Caplan, Charles Horowitz, Cecilia Lunardini The direct URCA process of rapid neutrino emission can occur in nonuniform nuclear pasta phases that are expected in the inner crust of neutron stars. Here, the periodic potential for a nucleon in nuclear pasta allows momentum conservation to be satisfied for direct URCA reactions. We improve on earlier work by modeling a rich variety of pasta phases (gnocchi, waffle, lasagna, and anti-spaghetti) with large-scale molecular dynamics simulations. We find that the neutrino luminosity due to direct URCA reactions in nuclear pasta can be 3 to 4 orders of magnitude larger than that from the modified URCA process in the neutron star core. Thus neutrino radiation from pasta could dominate radiation from the core and this could significantly impact the cooling of neutron stars. [Preview Abstract] |
|
SP01.00042: Comparison of vBAG and vMIT Bag Models at Finite Temperature Cristien Arzate, Thomas Klaehn The observation of neutron stars with masses $\sim 2 M_{\odot}$ supports the idea that quark matter exists in the cores of neutron stars. However, to construct effective theoretical frameworks which can successfully model the dense matter found inside neutron stars, one must take into account vector repulsion between interacting quarks.The vBAG and vMIT bag models of quark matter are examples of such frameworks and have been useful tools in the study of neutron stars. Here, we present a finite temperature extension to vBAG and vMIT which utilizes a Sommerfeld expansion to approximate the behavior of dense matter at low finite temperatures. This is relevant for large parameter space studies of proto-neutron stars as formed during supernovae and during neutron star mergers. The results of this work can also aid in the study of sound speeds for use in the investigation of gravitational waves observed by LIGO. [Preview Abstract] |
|
SP01.00043: Constraining Fermilab long-baseline neutrino fluxes Nilay Bostan The determination of the neutrino flux presents a challenge for the current and upcoming long-baseline neutrino experiments. The dominant uncertainty comes from the hadronic cascade model in the beamline. Fermilab experiments, such as DUNE and NO$\nu$A, use external hadron production data to constrain the models in their simulations and predict the neutrino flux at their detectors. Cross-section measurements from NA49 (CERN) are currently used for proton interactions and their impact is to reduce the flux uncertainty significantly. However, the simulation of interacting pions is not currently constraint by external data and a large uncertainty (40\%) is assumed. Recently, the NA61 experiment (CERN) released differential cross-section measurements of 60 GeV pions interacting in Carbon and Beryllium. In this talk, I will present the status of incorporating NA61 data to constrain these interactions and its impact in the neutrino flux for the DUNE and NO$\nu$A experiments. [Preview Abstract] |
|
SP01.00044: Neutron-Induced Backgrounds on Germanium-76 for Neutrinoless Double-Beta Decay Studies Joshua Adams, Mary Kidd, Sean Finch, Werner Tornow There are many large-scale experiments attempting to measure the neutrinoless double-beta decay of $^{\mathrm{76}}$Ge. As in many rare-event searches, it is vital to understand the potential backgrounds present. One potential background is due to neutron-induced gamma rays emitted by $^{\mathrm{76}}$Ge in the process of neutron inelastic scattering. The Q-value for neutrinoless double-beta decay of $^{\mathrm{76}}$Ge is 2039 keV, so gamma rays emitted in the de-excitation of $^{\mathrm{76}}$Ge above that value are of interest. In this study, we report cross-section results for an incident neutron energy of 4.5 MeV. [Preview Abstract] |
|
SP01.00045: Measurement of Electron Lifetime by the LAr Purity Monitoring System at ProtoDUNE-SP Nitish Nayak The DUNE experiment is part of the next generation of neutrino oscillation experiments that seek to definitively answer key questions in the field. It will utilize liquid argon time projection chambers (LArTPCs) enabling sub-mm spatial resolutions for unprecedented sensitivity. As part of prototyping designs for such a detector, in particular the single-phase (SP) and dual-phase (DP) technologies, two ProtoDUNE detectors were built at the CERN Neutrino Platform. ProtoDUNE-SP was commissioned in Fall 2018, with test beam data taken immediately after that. A key component of the LArTPC energy calibration is the drift electron lifetime which corrects the charge attenuation caused by drift electrons captured by impurities. In this talk, I shall describe the analysis for measuring electron lifetimes with the PrM system and using that to perform a run-by-run calibration of the LArTPC charge response. This is a complementary analysis to the Cosmic Ray Tagger (CRT)-based measurement of the lifetime within the TPC volume and has important implications for DUNE where the CRT-based methods will be more challenging due to the lack of cosmic statistics. [Preview Abstract] |
|
SP01.00046: Determination of hadronic activity near the neutrino interaction vertex for the NOvA cross-section measurements Chatura Kuruppu NOvA is a long-baseline neutrino oscillation experiment with two functionally identical detectors that use Fermilab's NuMI beam. NOvA is designed to measure the neutrino mixing angles and to discover the neutrino mass hierarchy, probe leptonic CP violation by measuring the oscillation of muon (anti)neutrinos to electron (anti)neutrinos between the near detector at Fermilab and the near detector in Ash River, Minnesota. The near detector provides an excellent platform to perform high-statistics studies of neutrino-nucleus interactions. The observation of this hadronic activity is of great importance of the identification of rare interactions such as charged-current coherent interactions. This poster will explain the importance of determining hadronic activity near the neutrino interaction vertex, how it's been determined, and its application to neutrino-nucleus scattering analyses. [Preview Abstract] |
|
SP01.00047: High performance hot neutron polarizer based on in-situ polarized 3He neutron spin filter Earl Babcock, Zahir Salhi, Vladimir Hutanu We have developed compact and high performance in-situ $^3$He polarizers based on spin-exchange optical pumping for the polarization and polarization analysis of hot (wavelengths from 0.3 to 1.1 \AA, and energy from 60 to 1000 meV) neutrons. Efficient polarization of neutrons of these wavelengths/energies is difficult to perform. Our $^3$He polarizers have been commissioned and used for 0.9 \AA neutrons where neutron polarizations in excess of 97 \% with over 24 \% neutron transmission are achieved. The performance can easily be extended to 0.3 \AA neutrons as would be available on the POLI instrument at the MLZ in Germany[1] by utilizing a higher pressure 3He cell. Consequently we are in the processes of completing an upgraded polarizer design optimized for this neutron instrument that can also operate in the vicinity of the available 8 T sample magnet. These polarizers will be used for studies of magnetism in single crystal neutron diffraction as well and fundamental and particle physics. Using the double focused beam of POLI they enable one of the most intense polarized hot neutron beams available. [1]Heinz Maier-Leibnitz Zentrum. (2015). POLI: Polarised hot neutron diffractometer. Journal of large-scale research facilities, 1, A16. http://dx.doi.org/10.17815/jlsrf-1-22 [Preview Abstract] |
|
SP01.00048: Revisiting the Issue of an Imaginary Energy Quantity That Appears in Near-Dirac Equations Wen-Tai Lin The result of minimal coupling with electromagnetic field would yield a real energy term attributed to the interface of a Dirac particle with an external magnetic field (via an inherent magnetic moment). Another term appears as an imaginary ``electric dipole moment'' coupled to an external electric field. The imaginary term, which also showed in Dirac's 1928 paper, has been purposefully removed via Hamiltonian transformations that are non-unitary in nature. The issue is revisited here because: (1) similar issue also appears in photon equations; and (2) there may be better interpretations/implications for it. It is asserted that an imaginary energy term in a quantum mechanical system is meant to be maintained as zero in system's stationary states, but imaginary energy could arise above zero in transient modes. Under certain circumstances, tachyon-type of communication mode allows for higher than the speed-of-light entangled events to occur. For example, in a multi-electron system, the imaginary energy term may serve as a means for forming electron pairs (or entangled particles) such that the aforementioned ``electric dipole moments'' are summed to zero. [Preview Abstract] |
|
SP01.00049: Israel-Stewart-like equations for non-relativistic viscous fluids Ariel Lerman, Jorge Noronha The equations of motion of non-relativistic viscous fluids are generalized to include nonlinear relaxation-type equations that describe how viscous fluxes relax towards their standard Navier-Stokes expressions. The new equations of motion provide a non-relativistic version of the famous relativistic Israel-Stewart equations commonly applied to the description of the quark-gluon plasma formed in heavy-ion collisions. We investigate the mathematical properties of these non-relativistic equations, proving that they are hyperbolic (in the full nonlinear regime) and stable against small disturbances around equilibrium. We numerically solve in 1$+$1 dimensions the case where only bulk viscosity is taken into account and compare the solutions to the corresponding ones obtained from the relativistic Israel-Stewart equations. [Preview Abstract] |
|
SP01.00050: Signatures of Chiral Magnetic Effect in the Collisions of Isobars Jinfeng Liao Quantum anomaly is a fundamental feature of chiral fermions. In chiral materials, the microscopic anomaly leads to nontrivial macroscopic transport processes such as the chiral magnetic effect (CME), which has been in the spotlight lately across disciplines of physics. The quark-gluon plasma (QGP) created in relativistic nuclear collisions provides the unique example of a chiral material consisting of intrinsically relativistic chiral fermions. Potential discovery of CME in QGP is of utmost significance, with extensive experimental searches carried out over the past decade. A decisive new collider experiment, dedicated to detecting CME in the collisions of isobars, was performed in 2018 with analysis now underway. This contribution repots the latest theoretical results that play a pivotal role for such ongoing experimental search. We develop the state-of-the-art tool for describing CME phenomena in these collisions and propose an isobar subtraction strategy for best background removal. Based on that, we make quantitative predictions for signatures of CME in the collisions of isobars as well as propose a new and robust observable that is independent of axial charge uncertainty. Reference: Shuzhe Shi, Hui Zhang, Defu Hou, and Jinfeng Liao, Phys. Rev. Lett. 125, 242301(2020). [Preview Abstract] |
|
SP01.00051: On the study of correlations among fragments in heavy ion collisions at intermediate energies Rohit Kumar, Sucheta ., Rajeev Puri \section{The microscopic many-body approaches such as quantum molecular dynamics model are used study heavy-ion collisions at intermediate energies and facilitate the extraction of nuclear matter properties at hot and dense conditions. The generated nucleonic information of these approaches is used to obtain fragments using r or p-space proximity of nucleons. More complex ones use energy minimization of fragmenting system [1]. Here, we will show the role played by changing the clusterization algorithm on the fragment-fragment correlations within the events. } \section{[1] R. Kumar et al., Phys. Rev. C 97, 034624 (2018).} [Preview Abstract] |
|
SP01.00052: Impact parameter determination using Machine learning algorithms C.Y. Tsang, M.B. Tsang, YongJia Wang Determination of impact parameter is a challenge for experimentalists because it cannot be measured directly. Using transport model simulations, it has been demonstrated that machine learning algorithms can infer impact parameter from experimental observables. However, unlike simulations, detection limitations such as geometric efficiencies and energy thresholds of the detector may affect the ability of machine learning to infer impact parameters. In this talk, we will discuss the impact parameter determination using machine learning in the collisions of $^{\mathrm{132}}$Sn$+^{\mathrm{124}}$Sn system at 270 MeV/u using charged particles detected by the S$\pi $RIT Time Projection Chamber. We will also discuss how we validate that the impact parameters determined from machine learning is indeed more accurate than that obtained by various experimental observables. [Preview Abstract] |
|
SP01.00053: $\textit{Ab initio}$ Method for Examining the Halo Structure of $^6$He Mengyao Huang, Robert Basili, Pieter Maris, James P. Vary, Tobias Frederico, Patrick J. Fasano, Mark A. Caprio We solve for the ground states of $^4$He and $^6$He with $\textit{ab initio}$ configuration interaction methods using the Daejeon16 nucleon-nucleon (NN) interaction. Using the full ground state wave functions, we evaluate pairwise correlations to characterize the structures of these two systems. First, we examine the pairwise correlations in the individual NN channels to isolate the similarities and differences of these two systems. We then evaluate and compare the coordinate-space separations of the two-proton subsystem, the neutron-proton pairs and the neutron-neutron pairs for these two systems. Finally, we use these coordinate-space pair correlations to address the halo structure of $^6$He relative to $^4$He. [Preview Abstract] |
|
SP01.00054: QCD resummation in the lattice calculation of PDFs Yong Zhao, Xiang Gao, Kyle Lee, Swagato Mukherjee Many nowadays lattice QCD approaches to calculate the parton distribution functions (PDFs) rely on a factorization formula or effective theory expansion to extract them from certain Euclidean matrix elements in boosted hadron states. In the threshold region as $x\to1$, the perturbative matching in the factorization or expansion formula includes large logarithms of $(1-x)$ that need to be resummed, which could affect the prediction of the large-$x$ behavior of PDFs. In this talk, we discuss the threshold resummation in the large-momentum effective theory and pseudo distribution approaches, and apply it to the lattice data for the pion valence quark PDF. Our analysis shows that with the current data quality and highest pion momentum $P^z=2.4$ GeV, the effect of threshold resummation is negligible for the lowest moments and large-$x$ behavior of the PDF. [Preview Abstract] |
|
SP01.00055: Creation of the Type-0 services for the ATLAS Inner Tracker Pixel Upgrade Evan Van De Wall In the mid-2020s, the Large Hadron Collider (LHC) will be shut down to undergo an upgrade to the High-Luminosity LHC. This upgrade will increase the number of collisions by an order of magnitude, resulting in over 200 collisions per bunch crossing. The increase in radiation and collision rate requires the inner detector to be upgraded to an all-new silicon-based tracking system called the Inner Tracker (ITk). This talk presents the work done to create the type-0 services that will be used in the ITk pixel detector. The work used a combination of simulations and prototype measurements to model signal integrity for the final design. [Preview Abstract] |
|
SP01.00056: Design and Status of a Multi-Reflection Time-of-Flight Mass Separator for the CHIP-TRAP Penning Trap Mass Spectrometer at Central Michigan University R Bhandari, MH Gamage, ND Gamage, M Redshaw, P Snoad At Central Michigan University (CMU), we are developing the CMU High Precision Penning trap (CHIP-TRAP), with the aim of performing high-precision mass measurements on stable and long-lived radioactive isotopes. CHIP-TRAP utilizes a laser ablation source and a Penning ion trap source to produce ions from solid and gaseous samples, respectively. In either case, contaminant ions are produced along with the ions of interest. To increase efficiency and sensitivity to ions produced in small quantities, such as radioactive ions, contaminant ions must be removed before they reach the Penning trap. To this end, we are implementing a multi-reflection time-of-flight mass separator (MR-TOF-MS) between the ion sources and Penning trap. Ions confined in the MR-TOF-MS are reflected between electrostatic mirror electrodes, increasing their effective path length and separating bunches of ions based on their $m/q$ ratio. After they are released from the MR-TOF-MS, a Bradbury-Nielsen gate will pass only the ions of interest. In this presentation, I will discuss the design of the MR-TOF-MS, present the analysis of simulations to optimize the electrode voltages, and provide an update on the current status of the installation and commissioning of the recently assembled MR-TOF-MS [Preview Abstract] |
|
SP01.00057: Fast Digital Signal Processing Using FPGAs for Nuclear Physics Experiments John Wilson, Jason Fry A field-programmable gate array (FPGA) possesses speed and performance comparable to a hardwired integrated circuit but packs a much higher versatility. FPGAs are becoming a realistic and useful replacement for analog signal processors because of their adaptability and capacity for complex filters. Though a fully functional computational device does not have the speed nor the delicacy to filter high throughput waveform data, FPGAs that do are increasingly available. Contemporary experiments in precise nuclear physics may benefit significantly from the sophisticated yet fast filters that can be executed on these systems. We are presently developing signal processing tools in a high-end FPGA to apply in nuclear particle detection. We will report on the progress of implementing impulse response filters on an advanced Xilinx RFSoC for use in such experiments. [Preview Abstract] |
|
SP01.00058: A direct sampling RF receiver for precise beam charge measurement Shujie Li, Yury Kolomensky, Yuan Mei, Ernst Sichtermann We demonstrate an RF receiver design that employs a direct digital sampling architecture. In September 2020, this receiver was installed at Jefferson Lab for its first beam test. It took signals from two beam intensity monitoring cavities on the Hall A beamline. With a 130uA beam current, it achieved 25ppm uncertainty in measuring the amplitude of a 1497MHz sinusoidal signal in a 0.5ms integration window. This device can be used for future parity-violation experiments, e.g. the MOLLER experiment to improve their beam charge uncertainties. [Preview Abstract] |
|
SP01.00059: Regions of pion production in Semi-Inclusive Deep Inelastic Scattering Alexei Prokudin, Mariaelena Boglione, Markus Diefenthaler, Leonard Gamberg, Scott Dolan, Nobuo Sato, Wally Melnitchouk, Daniel Pitonyak, Ted Rogers We study pion production in Semi-Inclusive Deep Inelastic Scattering (SIDIS) and identify various origins of pion production such as current Transverse Momentum Dependent and collinear regions , target, and soft fragmentation regions. In order to guide our intuition we propose a tool that enables one to assess the probability of a particular experimental bin to belong to one (or more) of those regions. The criterium we call affinity is based on a Monte Carlo generation of underlying kinematics of partons and the assessment of the most probable flow of momenta. The affinity tool is applied to the future SIDIS data from the Electron Ion Collider and Jefferson Lab 12 GeV upgrade. [Preview Abstract] |
|
SP01.00060: Nucleon structure in the covariant parton model Saman Bastami, Anatoli Vasilievich Efremov, Peter Schweitzer, Oleg Teryaev, Petr Zavada I will present a generalization of the covariant parton model that describes the quark correlators in a systematic way. This new version of the model allows for the first time to evaluate all T-even twist-3 transverse momentum dependent parton distribution functions (TMDs), and reproduces the T-even leading-twist TMDs from the original version. The fully unintegrated quark correlator is also evaluated in this approach, which allows us to understand the model-specific relations between different TMDs. The consistency of the approach is discussed and numerical results with comparisons to available TMD parametrizations are provided. [Preview Abstract] |
|
SP01.00061: LHCb Charm Pentaquark Search with SoLID Detector in Hall A at Jefferson Lab Burcu Duran Four years after the initial discovery of the hidden-charm pentaquarks by LHCb, the collaboration released new results in 2019 indicating the discovery of a new pentaquark, while the $P_c$(4450) state resolved into a double peak structure. Although the theory community produced numerous publications interpreting the results, the LHCb experiment remains the only experiment that observed these states. Jefferson Lab has an extensive experimental program in all four experimental halls to study the LHCb hidden-charm pentaquarks' nature. The recent Hall C $J/\psi$ experiment (E12-16-007) used a high-intensity real photon beam to search for these states at high values of the proton momentum transfer $|t|$, maximizing the sensitivity to these $s$-channel resonances. The SoLID-$J/\psi$ experiment will combine high luminosity and large acceptance to measure $J/\psi$ electro- and photo-production in the threshold region with unprecedented statistical precision. In this talk, I will discuss the impact of the SoLID-$J/\psi$ experiment on the LHCb hidden-charm pentaquark search. [Preview Abstract] |
|
SP01.00062: Early test of photosensors in high rate environment for gas Cherenkov Junqi Xie, Chao Peng, Sylvester Joosten, Zein-Eddine Meziani, Alexandre Camsonne, Mark Jones, Edward Kaczanowicz, Melanie Rehfuss, Nikolaos Sparveris, Michael Paolone, Michael Foley, Michael Minot, Mark Popecki The upcoming SoLID experiment at Jefferson Lab will push the intensity frontier for a large-acceptance detector, requiring the use of a light-gas Cherenkov detector for trigger-level event selection. It is essential to validate the planned photosensors and readout electronics in high rate environment to determine the limits of these sensors and mitigate the risk of failure of the trigger-level event selection. We report a set of early studies of available photosensors and electronics using a small prototype telescopic Cherenkov device. Commercially available multi-anode photomultipliers (MaPMT) and low-cost large-area picosecond photodetectors (LAPPD) were tested with the JLab FADC250 modules for the data acquisition to assess their performance in such an environment. The experiment results show that both an MaPMT array and an internal stripline LAPPD could detect the Cherenkov signals and resolve single-electron events and pair production events. A GEANT4 simulation confirms the experimental performance of the prototype results through direct comparison. Detailed experiment results will be presented and suggested future tests will be discussed. [Preview Abstract] |
|
SP01.00063: RADIATION SOURCES |
|
SP01.00064: Nuclear energy as a true climate savior in terms of risk (Fukushima), waste, sustainability and greenhouse gas emissions. Robert Hayes Research has shown that all radiation doses from Fukushima were too low to generate any statistically significant medical effects. The evacuation did kill almost 2000 people and radiophobia has since been creating serious stress related medical outcomes (e.g., hypertension, weight gain). Shielding and transportation of radioactive sources such as high level waste has been well understood and implemented for many decades. With the overwhelming scientific evidence for the safe geological disposal of spent nuclear fuel being blocked only by politics, the lack of greenhouse gas emissions from this baseload providing and dispatchable nuclear energy source is extremely compelling. With new research showing that ocean extraction of naturally dissolved primordial actinides supplied by river water is being replenished (via erosion and plate technonic renewal) at around 10x the current US energy usage annual rate now makes nuclear energy renewable. Recycling technology can burn all long lived fission products and utilize depleted uranium from prior fuel manufacture allowing fuel cycles which are truly sustainable. All of this begs the question as to whether nuclear energy is truly the climate savior we are seeking. [Preview Abstract] |
|
SP01.00065: DATA SCIENCE |
|
SP01.00066: Predicting the First and Last Frost using Historical Data and Numerical Weather Predictions Joseph Trout, Courtney Weber Community gardens have become and effective and popular way to increase the variety of nutritional foods in food deserts, especially inner-city food deserts. Community gardens in the city of Philadelphia have been experiencing problems with disease and pests, especially for the tomato plants. The tomato plants would mature until harvest time, and then experience problems when the tomato plants were stressed by the hottest part of summer. The heat of the summer is magnified by the urban heat island effect. One solution is to grow tomato varieties with short growing periods. In order for this to be effective, an accurate prediction of the last frost of the spring and first frost of the fall is required. This project looks at using historical data and the Weather Research and Forecasting (WRF) Model to predict the seasonal frosts. [Preview Abstract] |
|
SP01.00067: Bayesian Density Estimation with Voronoi Tessellations on Spatial Data Konstantin Matchev, Alex Roman, Prasanth Shyamsundar Relevant information from collision events from the Large Hadron Collider (LHC) and other colliders can be represented as spatial data in the appropriate phase space. Features such as sharp discontinuities in the event number density may signal the presence of new physics. Extraction of features from the data relies upon estimation of the functional value of the underlying distribution. We attempt to use properties of the Voronoi tessellation along with Neural Networks and Bayesian Networks of the data to improve upon traditional methods of density estimation. [Preview Abstract] |
|
SP01.00068: Machine Learning based tracking at the trigger level Syed Haider Abidi, Antonio Boveia, Viviana Cavaliere, Alex Gekow, William Kalderon, Jiancong Zeng Triggers at high luminosity colliders play an important role in ensuring high sensitivity to new physics and signatures while keeping the data storage requirements at acceptable levels. This will be especially crucial in the next runs of the LHC and at the HL-LHC. Rather than simply imposing stricter pT or isolation requirements to keep trigger rates low, we explore the use of tracking requirements at trigger level. We present a NN based approach in identifying hits coming from a track. In this bottom-up, the complexity and input information are minimized to allow the NN to be implemented on a FPGA. This hardware based approach allows for increased data throughput, shorter latency and, crucially, flexibility to improve the algorithm in the future. [Preview Abstract] |
|
SP01.00069: GENERAL POSTERS GENERAL POSTERS [Preview Abstract] |
|
SP01.00070: Stability, electronic and optical properties in ternary nitride phases of MgSnN2: A first principles study Bishal Dumre, Daniel Gall, Sanjay Khare We studied the disordered-rocksalt, orthorhombic and disordered-wurtzite phases of the ternary nitride semiconductor MgSnN2 from first principles methods using density functional theory (DFT). We find that MgSnN2 is mechanically and dynamically stable in all three phases. However, COHP analysis suggests that the disordered rocksalt structure has anti-bonding states below the Fermi level between -5 eV to -2 eV as compared to the bonding states in other two phases, indicating thermodynamic metastability. Computed lattice constant and electronic band gap values of 4.56 Å and 2.69 eV of MgSnN2 in disordered rocksalt structure compare well with experimentally reported values of 4.48 Å and 2.3 eV respectively. Furthermore, band gaps were computed in MgSnN2-xOx, with x = 0.5, 1.0, 1.5, 2.0, to elucidate the role of possible oxygen impurity. Of the three phases, disordered-rocksalt structure shows the lowest charge carrier effective masses. Moreover, this phase has promising absorption coefficient and reflectivity to be used as the absorber layer of tandem solar cells in the higher energy region of the visible portion of the solar spectrum. The other two phases can be utilized as a window layer of solar cells owing to their larger band gap values of 4.36 eV and 4.86 eV respectively. [Preview Abstract] |
|
SP01.00071: Theory Testing and Eclipses Daniel Kennefick The 1919 eclipse test is widely considered to be one of the classic examples of theory testing in scientific history. So successful was this famous test that following it most theory testing in gravitational physics focused on metric theories of gravity. This talk looks at the role of 20th century eclipse tests in discriminating between metric theories of gravity. Examples include Nordstrom’s theory and the Jordan-Brans-Dicke theory, which was the subject of interest in the last professionally mounted light deflection eclipse expedition, by the University of Texas in 1973. By then the parametrized post-Newtonian framework had been developed as a tool to enable theory testing of this kind. The question of how important eclipse tests were in this endeavor is considered. [Preview Abstract] |
|
SP01.00072: Binomial coefficients and Arithmetic Progression in an Alternating Series with its interpretation in Vector Space Nitika Sachdeva A series is defined using terms of arithmetic sequence taken along with binomial coefficients nCr. By deriving it in all the subsequent sections of Pascal's hexagon, the series is extended for nCr where n,r belong to R.Further, it is analysed in a vector space and is found to be a subspace of it. The series is studied as a scalar product of three-dimensional vectors where some of the findings are generalized for n-dimensions. [Preview Abstract] |
|
SP01.00073: Physics-informed, empirically constrained machine learning for designing Fe-9Cr alloys Vyacheslav Romanov Materials data analytics can be used to significantly shorten development time of specialized alloys needed for next generation energy applications. Incorporation of the domain knowledge into deep-learning graph structure via fuzzy pre-training and causal process imitation presents a viable approach to developing accurate data-driven models and reliable alloy design tools, with limited datasets. It was demonstrated that the domain knowledge-based empirical constraints not only inhibit overfitting but also allow training more accurate and reliable ML models with improved transparency of the output interpretation. In this study, alloy tensile properties were interpreted with three competing virtual-microstructure models. [Preview Abstract] |
|
SP01.00074: A New Gravity Perspective Frank Hafner There is a fifth spacetime dimension where the universe expands on two degrees of freedom, parallel and normal to light. At universe inception, near infinite mass density created near infinite spacetime curvature. Gravity applies in the normal dimension, light does not. From inception the path of light reduces curvature as spacetime unwinds with decreasing mass density. Dark energy is unwinding spacetime. A tetherball path around the pole is the parallel direction. The path away from the pole increasing one circumference per revolution is the normal direction. The normal direction accounts for quantum teleportation. The field equations and the gravitational constant are altered to account for five spacetime dimensions. The cosmological constant and inflation are eliminated. Time becomes an energy source due to time dilation equilibration caused by different time rates in parallel and normal expansion. This accounts for unexplained energy events - fast radio bursts\textellipsis Normal gravity contributes to dark matter applied to antimatter remnants caused by weak force change parity violation decay into space dependent information with gravity. All is information attributes spatially dependent or independent. Information $=$ Time $=$ E $=$ mc$^{\mathrm{2}}$. Spatially independent information is found prior to universe inception and in black hole singularities. Improved precision of time and physical phenomenon measurement will allow detection of gravitational quantum time dilation bringing gravity into the standard model. [Preview Abstract] |
|
SP01.00075: Paul Ehrenfest and the development of Kaluza-Klein theory. Paul Halpern In his position at Leiden, Paul Ehrenfest promoted inquiry-based dialogue among the visitors to the university, addressing a wide range of fundamental questions about physics. One such visitor, in summer 1916, was Finnish physicist Gunnar Nordstr\"{o}m, who had recently published a five-dimensional unification scheme. After discussions with Nordstr\"{o}m, Ehrenfest became interested in the question of dimensionality himself, and published a remarkable paper, ``In what way does it become manifest in the fundamental laws of~physics that space has three dimensions?'' We'll show in this talk the connections between Ehrenfest's work and the subsequent development of Kaluza-Klein theory: extending general relativity to embrace an extra dimension for the purpose of accommodating electromagnetic interactions. [Preview Abstract] |
|
SP01.00076: Piles of Piles: A survey of nuclear pile development during World War II Cameron Reed Between the time of the discovery of nuclear fission in early 1939 and late 1946, approximately 90 nuclear piles were constructed in six countries. About 60 of these were constructed in the United States, 20 in Germany, and a handful in Britain, France, Canada, and Russia. These devices included simple graphite columns containing only neutron sources, uncooled and cooled graphite and heavy-water moderated uranium-bearing models constructed in efforts to achieve criticality, and the enormous plutonium production reactors built at Hanford, Washington. This paper will review wartime pile developments, summarizing activities in different countries and pointing out interesting contrasts in design approaches. [Preview Abstract] |
|
SP01.00077: In appreciation of Joshua Goldberg (1925 -- 2020) Donald Salisbury Joshua Goldberg was a seminal contributor to relativity theory, both through his own original work and his function as an administrator of US Air Force research funding. He is perhaps best known for his work on algebraically special solutions of Einstein's equations, yet he also helped pave the way to our understanding of the generation and propagation of gravitational waves. He was in addition a leader in the exploration of the use of null surfaces and the description of asymptotic fields. I will give a brief overview of this work, frequently citing Josh's own comments in a series of interviews I recorded with him. [Preview Abstract] |
|
SP01.00078: Do Event Horizons Really Exist? Alan M. Kadin Black holes surrounded by event horizons are standard solutions of orthodox gravitational theory, and are universally believed to have been observed in galactic centers and binary stars. On the contrary, it is suggested here that the theory has never been proven in the strong-field regime, and that the convincing observations of compact astronomical objects do not validate the presence of event horizons with divergent spacetime. Indeed, it is easy to construct non-divergent spacetime models that give rise to compact objects without event horizons [1]. Recent detailed observations of black holes, such as those from the Event Horizon Telescope and the Laser Interferometric Gravitational-Wave Observatory, may be mostly confirmation bias of noisy data [2]. Until such time as the measurements have much higher resolution, the prudent scientific approach is to regard black holes and event horizons as interesting mathematical objects that may or may not exist in the real universe. [1] A.M. Kadin, ``Gravitation and Cosmology Without Divergences,'' 2018. \underline {https://vixra.org/abs/1804.0231} [2] A.M. Kadin, ``Why We Should Be Skeptical of Black Holes,'' 2020. \underline {https://vixra.org/abs/2005.0152} [Preview Abstract] |
|
SP01.00079: Probing the fission dynamics of $^{\mathrm{\mathbf{192,202}}}Po compound nuclei using neutron multiplicity measurements Ruchi Mahajan The dominant reaction mechanism for the nuclear reactions induced between heavy ions is fusion-fission (FF) as well as non-equilibrium process called quasi-fission (QF). In order to disentangle the FF and QF processes, we have measured the neutron multiplicity for $^{\mathrm{48}}$Ti $+^{\mathrm{144,154}}$Sm $\to^{\mathrm{192,202}}$Po compound nuclei. For the system $^{\mathrm{18}}$O $+^{\mathrm{192}}$Os $\to ^{\mathrm{210}}$Po, experimental data exists for neutron multiplicity. For systems with heavier projectile, sizable contribution from QF process is expected. We have performed a consistent analysis of Po (N$=$108 to 126) nuclei to study the role of shell effects. This experiment was performed using National Array of Neutron Detectors (NAND) facility at IUAC, New Delhi. The pre- and post-scission components of neutron multiplicities are obtained from the measured neutron energy spectra by using a multiple source least-square fitting procedure, using the Watt expression. Statistical model calculations were performed for these systems using Bohr Wheeler and Kramer's formalism [1]. [1] R. Mahajan \textit{et al.,} Phy. Rev. C 98, 034601 (2018). [Preview Abstract] |
|
SP01.00080: Towards an Interpretable Data-driven Trigger System for High-throughput Physics Facilities Chinmaya Mahesh, Kristin Dona, David W. Miller, Yuxin Chen, Cecilia Tosciri Data-intensive science is increasingly reliant on real-time processing capabilities and machine learning workflows, in order to filter and analyze the extreme volumes of data being collected. This is especially true at the intensity frontier of particle physics. Data filtering algorithms, or \textit{trigger algorithms}, at the LHC drive the data curation process, funneling event records with certain features into categories that are predefined based on the labels extracted by the trigger algorithms. The design, implementation, monitoring, and usage of these trigger algorithms is resource-intensive and can include significant blindspots. The \textit{menu} of trigger algorithms is manually designed based on domain knowledge (involving \textasciitilde 100 data filters). In this presentation, we introduce a new data-driven approach for designing and optimizing high-throughput data filtering and trigger systems such as those in use at physics facilities like the LHC. We introduce key insights from interpretable predictive modeling and cost-sensitive learning in order to account for non-local inefficiencies in the current paradigm and construct a cost-effective data filtering and trigger model that does not compromise physics coverage. [Preview Abstract] |
|
SP01.00081: P=/=NP(RSA) Trivial Proof via Menger Dimension-Theory(DT) Fluctuations(DFS) Table and Sipser Graphic: [Analogy to Siegel(64) FLT Proof]: Algorithmic- “Complexity”(AC) = Utter-Simplicity(US): NP-Completeness(NPC) aka Siegel “FUZZYICS”/(SPD/M)! Edward Siegel Algorithmic-“complexity”(AC)=utter-simplicity in Siegel P=/=NP(RSA) trivial proof via Menger[Dimensiontheorie(29)]/Polya[How to Solve It(45/73)-table] dimension-theory(DT) dimensionalty-fluctuations(DFS) table and Sipser[Intro./Thy.Computations(13)-fig.#1.15!] graphic. P “=” NP aka deterministic-polynomial P “=” NP aka deterministic-polynomial “=” non-deterministic polynomial aka DP “=” NP. dim(D) “=” dim(M) because P cancels: deterministic D is serial aka dim(D)=1 VS. dim (M)=2+E(if probabilistic) aka non-deterministic =planar forking-triangles simplex: 1<2+E(if probabilistic) aka 1=/= 2+E. Ergo P=/=NP! US!(analogy to Siegel (64)[<< |
|
SP01.00082: NP-Completeness via Nested-Ontologies(NOS): Siegel FUZZYICS in Aristotle “Square-of-Opposition”(SoO) in Aristotle Hierarchy-of-Thinking(HoT): P=/=NP Trivial Proof via Menger/Polya Dimension-Theory: Algorithmic-“Complexity”(AC)=Utter-Simplicity(US) Edward Siegel NP-completeness[Poundstone[Labyrinths of Reason(88)-ch.9/p.162]; Korte/Vygen[Comb.Optim.(02)-ch.15/p.327]] realization is via NOS: Siegel[Symp./Fractals,MRS Fall Mtg.,Boston(89)-6 pprs(read #2 pre #1);Symp./Transport within Geometric-Constraints,ibid(90)] FUZZYICS/(SPD/M) embedded within Aristotle/Copi[Symbolic-Logic(61)]/Horn [Linguistics/Yale]/Parsons [Philo./UCLA/Stanford Encycl./Philo.]/… “Square-of-Opposition”(SoO) in Aristotle/Altshuler (TRIZ)/Siegel “Hierarchy-of-Thinking”(HoT): AC = utter-simplicity in Siegel P=/=NP trivial
proof via Menger[Dimensiontheorie(29)]/Polya[How to Solve It(45/73)-table] dimension-theory(DT) dimensionalty-fluctuations(DFS) table and Sipser[Intro./Thy.Computations(13)-fig.#1.15!] graphic. P “=” NP aka deterministic-polynomial P “=” NP aka deterministic-polynomial “=” non-deterministic polynomial aka DP “=” NP. dim(D) “=” dim(M) because P cancels: deterministic D is serial aka dim(D)=1 VS. dim (M) = 2+E(if probabilistic) aka non-deterministic = planar forking-triangles simplex: 1<2+E(if probabilistic aka 1=/= 2+E. Ergo P=/=NP! Utter-Simplicity! (analogy to Siegel(64)[<< |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700