Bulletin of the American Physical Society
APS April Meeting 2017
Volume 62, Number 1
Saturday–Tuesday, January 28–31, 2017; Washington, DC
Session C2: Undergraduate Research/SPS IIUndergraduate
|
Hide Abstracts |
Sponsoring Units: APS SPS Chair: Crystal Bailey, APS Room: Maryland B |
Saturday, January 28, 2017 1:30PM - 1:42PM |
C2.00001: Novel Tests of Gravity at the Sub-millimeter Scale Gabriela Martinez, Jeremy Johnson, Ian Guerrero, C.D. Hoyle Due to inconsistencies between General Relativity and the Standard Model, tests of gravity remain at the forefront of experimental physics. At Humboldt State University, undergraduates and faculty are designing an experiment sensitive enough to detect gravitational interactions below the 50 micron scale. The experiment measures the twist of a torsion pendulum as an attractor mass is oscillated nearby in a parallel plate configuration, providing time varying gravitational torque on the pendulum. The size and distance dependence of the torque variation will provide a means to determine any deviation from current models of gravity on untested scales. This talk will focus on the implementation of an optical encoder to measure the attractor position as well as a brief overview of other experimental upgrades. [Preview Abstract] |
Saturday, January 28, 2017 1:42PM - 1:54PM |
C2.00002: Covariance and Quantum Cosmology: A Comparison of Two Matter Clocks Theodore Halnon, Martin Bojowald In relativity, time is relative between reference frames. However, quantum mechanics requires a specific time coordinate in order to write an evolution equation for wave functions. This difference between the two theories leads to the problem of time in quantum gravity. One method to study quantum relativity is to interpret the dynamics of a matter field as a clock. In order to test the relationship between different reference frames, an isotropic cosmological model with two matter ingredients is introduced. One is given by a scalar field and one by vacuum energy or a cosmological constant. There are two matter fields, and thus two different Hamiltonians are derived from the respective clock rates. Semi-classical solutions are found for these equations and a comparison is made of the physical predictions that they imply. [Preview Abstract] |
Saturday, January 28, 2017 1:54PM - 2:06PM |
C2.00003: Comparison of Alternative Gravity Models in Dwarf Galaxy Rotation Curves Justin Harrington, Taylor Saintable, James O'Brien Galactic rotation curves have proven to be the testing ground for dark matter bounds in spiral galaxies of all morphologies. Dwarf Galaxies serve as an increasingly interesting testing ground of rotation curve dynamics due to their increased stellar formation and typically rising rotation curve. These galaxies usually are not dominated by typical stellar structure and mostly terminate at small radial distances. This, coupled with the fact that Cold Dark Matter theories such as NFW (ΛCDM) struggle with the universality of galactic rotation curves, allow for exclusive features of alternative gravitational models to be analyzed. Here, we present a thorough application of alternative gravitational models (conformal gravity and MOND) to a 2010 dwarf galaxy sample from Swaters et al. An analysis and discussion of the results of the fitting procedure of the two alternative gravitational models are explored. We posit here that both the Conformal Gravity and MOND can provide an accurate description of the galactic dynamics without the need for copious dark matter. [Preview Abstract] |
Saturday, January 28, 2017 2:06PM - 2:18PM |
C2.00004: Theoretical Comparison Between Candidates for Dark Matter James Mckeough, Ajit Hira, Alexandra Valdez Since the generally-accepted view among astrophysicists is that the matter component of the universe is mostly dark matter, the search for dark matter particles continues unabated. The Large Underground Xenon (LUX) improvements, aided by advanced computer simulations at the U.S. Department of Energy's Lawrence Berkeley National Laboratory's (Berkeley Lab) National Energy Research Scientific Computing Center (NERSC) and Brown University's Center for Computation and Visualization (CCV), can potentially eliminate some particle models of dark matter. Generally, the proposed candidates can be put in three categories: baryonic dark matter, hot dark matter, and cold dark matter. The Lightest Supersymmetric Particle\textbf{ (}LSP) of supersymmetric models is a dark matter candidate, and is classified as a Weakly Interacting Massive Particle (WIMP). Similar to the cosmic microwave background radiation left over from the Big Bang, there is a background of low-energy neutrinos in our Universe. According to some researchers, these may be the explanation for the dark matter. One advantage of the Neutrino Model is that they are known to exist. Dark matter made from neutrinos is termed "hot dark matter". We formulate a novel empirical function for the average density profile of cosmic voids, identified via the watershed technique in $\Lambda $CDM N-body simulations. This function adequately treats both void size and redshift, and describes the scale radius and the central density of voids. We started with a five-parameter model. Our research is mainly on LSP and Neutrino models. [Preview Abstract] |
Saturday, January 28, 2017 2:18PM - 2:30PM |
C2.00005: Study of enhancing a hadronic search for supersymmetry with quark/gluon discrimination Louis Penafiel We present studies of applying quark/gluon discrimination in the context of searches for supersymmetry in all hadronic final states with data from the Compact Muon Solenoid experiment. We compare the sensitivity of an established search with a search that utilizes the additional information from quark/gluon discrimination. Results are shown for several simplified model signal topologies. [Preview Abstract] |
Saturday, January 28, 2017 2:30PM - 2:42PM |
C2.00006: The Fast Interaction Trigger Detector of ALICE at the LHC Keenan Lambert, Shanice Brown, Calvin Powell, Austin Harton, Edmundo Garcia-Solis CERN (European Center for Nuclear Research) is a global laboratory that studies proton and heavy ion collisions at the Large Hadron Collider (LHC). ALICE (A Large Ion Collider Experiment) is one of four large experiments at the LHC. ALICE is dedicated to the study of the transition of matter to Quark-Gluon Plasma in heavy ion collisions. The experiment is preparing for the LHC upgrade after the second long shutdown (LS2) in 2019-20. To this end, ALICE is undertaking a major initiative to extend its physics capabilities. Among these improvements is a new Fast Interaction Trigger (FIT). The FIT will be replacing the current T0 and V0 trigger detectors. The purpose of the FIT will be to determine multiplicity, centrality, and reaction plane. The FIT will also serve as the primary forward trigger, luminosity, and collision time detector. This presentation will discuss the FIT upgrade and the results from the performance of the FIT detectors in simulations and test beams that support the current design parameters. This material is based upon work supported by the National Science Foundation under grants NSF-PHY-1407051, NSF-PHY-1305280, NSF-PHY-1613118, and NSF-PHY- 1625081. [Preview Abstract] |
Saturday, January 28, 2017 2:42PM - 2:54PM |
C2.00007: Studying B-Tagging Performance for new physics searches with the CMS Detector at the LHC David Last Theoretical models for BSM physics often predict new particles that predominantly decay to b-quarks. The CMS (Compact Muon Solenoid) detector at CERN is one of two general purpose detectors collecting data from the LHC (Large Hadron Collider). A~subset of the data, known as ``Scouting'' is collected with lower trigger thresholds than the nominal data acquisition paths, which allows searches for new physics with final state jets in lower mass region. Examples include searches for resonances in dijets, three-jets and paired dijets.~ The b-tagged version of all these low-mass analyses will benefit from an independent understanding of the b-tagging performance of jets in the Scouting dataset. In this study, we examine the purity and efficiency of the CSV (Combined Secondary Vertex) variable in the Scouting dataset to identify a b-jet.~ We isolate a sample of jet-triplets rich in hadronic top quark decays without any requirement on the b-tagging within the triplet, and examine the CSV value of the b-jet from top decay. [Preview Abstract] |
Saturday, January 28, 2017 2:54PM - 3:06PM |
C2.00008: Title: Seesaw Search with Multilepton Final States using 13 TeV LHC Data Grace Haza Results of a search for Seesaw Type-III heavy fermions in final states with at least three charged leptons are presented. The data sample corresponds to $2.1\,\textrm{fb}^{-1}$ of integrated luminosity in proton--proton collisions at $\sqrt{s} = 13\,\textrm{TeV}$ collected by the CMS experiment at the LHC. Data is binned in exclusive channels by categorizing in various quantities like the number of leptons, missing transverse energy, or whether the event properties are consistent with the production of a Z boson. Sensitivity improves by using transverse mass as a selection variable and is expected to improve substantially with approximately $40\,\textrm{fb}^{-1}$ of integrated luminosity. [Preview Abstract] |
Saturday, January 28, 2017 3:06PM - 3:18PM |
C2.00009: Improving calorimeter resolution using temperature compensation calculations Joseph Smiga, Martin Purschke The sPHENIX experiment is an upgrade of the existing PHENIX apparatus at the Relativistic Heavy-Ion Collider (RHIC). The new detector improves upon measurements of various physical processes, such as jets of particles created during heavy-ion collisions. Prototypes of various calorimeter components were tested at the Fermilab Test Beam Facility (FTBF). This analysis tries to compensate the effects of temperature drifts in the silicon photomultipliers (SiPMs). Temperature data were used to calculate an appropriate compensation factor. This analysis will improve the achievable resolution and will also determine how accurately the temperature must be controlled in the final experiment. This will improve the performance of the calorimeters in the sPHENIX experiment. [Preview Abstract] |
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