Bulletin of the American Physical Society
APS April Meeting 2017
Volume 62, Number 1
Saturday–Tuesday, January 28–31, 2017; Washington, DC
Session C6: Precision Measurements and Fundamental Symmetries |
Hide Abstracts |
Sponsoring Units: GPMFC Chair: Thomas Gentile, NIST Room: Virginia C |
Saturday, January 28, 2017 1:30PM - 1:42PM |
C6.00001: A micromechanical proof-of-principle experiment for measuring the gravitational force of milligram masses Jonas Schmöle, Mathias Dragosits, Hans Hepach, Tobias Westphal, Markus Aspelmeyer We address a simple question: how small can one make a gravitational source mass and still detect its gravitational coupling to a nearby test mass? We describe an experimental scheme based on micromechanical sensing to observe gravity between milligram-scale source masses, thereby improving the current smallest source mass values by three orders of magnitude and possibly even more. We will discuss the present status of the experimental implementation and the implications of such measurements both for improved precision measurements of Newton's constant and for a new generation of experiments at the interface between quantum physics and gravity. [Preview Abstract] |
Saturday, January 28, 2017 1:42PM - 1:54PM |
C6.00002: First Results of the GPS.DM Observatory: Search for Dark Matter and Exotic Physics with Atomic Clocks and GPS Constellation Benjamin Roberts, Geoff Blewitt, Conner Dailey, Maxim Pospelov, Alex Rollings, Jeff Sherman, Wyatt Williams, Andrei Derevianko Despite the overwhelming cosmological evidence for the existence of dark matter, and the considerable effort of the scientific community over decades, there is no evidence for dark matter in terrestrial experiments. The GPS.DM observatory uses the existing GPS constellation as a 50,000 km-aperture sensor array, analysing the satellite and terrestrial atomic clock data for exotic physics signatures. In particular, the collaboration searches for evidence of transient variations of fundamental constants correlated with the Earth's galactic motion through the dark matter halo. There already exists more than 10 years of good clock timing data that can be used in the search. This type of search is particularly sensitive to exotic forms of dark matter, such as topological defects. A. Derevianko and M. Pospelov, Nat. Phys. 10, 933 (2014). [Preview Abstract] |
Saturday, January 28, 2017 1:54PM - 2:06PM |
C6.00003: NOPTREX, An Experiment to Search for T Violation in Polarized Neutron Optics Jonathan Curole, William Snow Sensitive experimental searches for new sources of time reversal violation can uncover new phenomena beyond the Standard Model of particle physics and may be important for our understanding of the baryon asymmetry of the universe. We describe the concept behind an experimental search for a P-odd and T-odd term in the polarized neutron-polarized nucleus forward scattering amplitude \footnote{V.P. Gudkov, Physics Reports {\bf 212 }, 77-105 (1992).}. This takes advantage of the approximate $10^{5}$\textemdash $10^{6}$ amplification of P-odd amplitudes in certain epithermal p-wave n-A resonances in nuclei such as $^{139}$La \footnote{V.P. Alfimenkov, L. Lason, Yu.D. Mareev, V.V. Novitsky, L.B. Pikelner, V.R. Skoy, M.I. Tsulaya, A.N. Chernikov, Phys. Atomic Nuclei {\bf 59}, 1861 (1996).}. A measurement of such a P-odd/T-odd forward amplitude constitutes a null test for T violation. Recent developments of MW-class spallation neutron sources, neutron polarization technology using $^{3}$He, and a motion-reversal-based measurement strategy enable a scientifically interesting sensitivity \footnote{V.P. Gudkov, J.D. Bowman, Phys. Rev. C {\bf 90 }, 065503 (2014).}. [Preview Abstract] |
Saturday, January 28, 2017 2:06PM - 2:18PM |
C6.00004: NOPTREX: A Search for Time Reversal Violation; Detector Development and Nuclear Spectroscopy on the 0.734 eV p-wave resonance in $^{139}$La Danielle Schaper Searches for new sources of time reversal (T) violation are one of the highest intellectual priorities in nuclear, particle, and astrophysics. The NOPTREX collaboration aims to conduct a sensitive null-test search for T violation in polarized neutron transmission through polarized nuclear targets which possess low energy p-wave resonances. One candidate nuclei of interest, $^{139}$La, has a 0.734 eV resonance which exhibits a very large parity-violating asymmetry. We will describe spectroscopy measurements which can provide useful, relevant information on this resonance such as preliminary "double lanthanum" parity violation measurements as well as discuss the design and construction of the neutron detector and rotation stage that will be used both for these tests and in the ultimate NOPTREX experiment. Reference: J.D. Bowman and V. Gudkov, Phys Rev C 90, 065503, 2014 [Preview Abstract] |
Saturday, January 28, 2017 2:18PM - 2:30PM |
C6.00005: Beyond Schiff Moment: Atomic EDMs from Two-Photon Exchange Satoru Inoue, Michael Ramsey-Musolf Atomic electric dipole moment (EDM) searches are some of the most sensitive tests of CP violation. Interpretation of atomic EDM searches requires careful consideration of the Schiff theorem, which states that a neutral system of non-relativistic point charges interacting only electrostatically has zero net EDM. Atomic EDMs arise from breakdowns in the assumptions to the Schiff theorem. Conventionally, leading contributions to EDMs of diamagnetic atoms are thought to be nuclear Schiff moments, which arise due to finite sizes of nuclei. We revisit the argument to derive the Schiff moment contribution to atomic EDMs and find that atomic EDMs can be generated from non-electrostatic interactions, namely 2 successive electron-nucleus interactions involving transverse electric multipoles. We estimate that this contribution can be comparable to the Schiff moment effect. [Preview Abstract] |
Saturday, January 28, 2017 2:30PM - 2:42PM |
C6.00006: Matching Contact Interactions in QED-NRQED Effective Field Theory Steven Dye, Matthew Gonderinger, Gil Paz In 2010 the proton charge radius was first extracted from muonic hydrogen and was found to have a value five standard deviations away from the regular hydrogen value. An effective field theory analysis using Non-Relativistic Quantum Electrodynamics (NRQED) indicates that the muonic hydrogen result can be interpreted as a large, compared to some model estimates, muon-proton spin-independent contact interaction. One of the most promising avenues to resolve this puzzle is by muon-proton scattering. Such an experiment, called MUSE, is planned at the Paul Scherrer Institute in Switzerland. The typical momenta of the muons in this experiment are of the order of the muon mass. In this energy regime the muons are relativistic but the protons are still non-relativistic. The interaction between them can be described by a QED-NRQED effective field theory. Here we present elements of this effective field theory. In particular, we look at $\mathcal{O}(Z\alpha)$ scattering up to power $m^{2}/M^{2}$, where m (M) is the muon (proton) mass, and $\mathcal{O}(Z^{2}\alpha^{2})$ scattering at leading power. We also take a brief look at $\mathcal{O}(Z^{2}\alpha^{2})$ at subleading power. [Preview Abstract] |
Saturday, January 28, 2017 2:42PM - 2:54PM |
C6.00007: High Precision Magnetic Field Scanning System for the New Muon g-2 Experiment Ran Hong The New Muon g-2 Experiment (E989) at Fermilab will measure the anomalous magnetic moment of muon $a_{\mu}$ aiming at a precision of 140 ppb. This new experiment will shed light on the long-standing 3.5 standard deviation between the previous muon g-2 measurement (E821) at Brookhaven National Laboratory and the Standard Model calculation, and potentially discover new physics. The New Muon g-2 Experiment measures the precession frequency of muon in a uniform magnetic field, and the magnetic field experienced by the muons needs to be measured with a precision better than 70 ppb. For the measurement of the magnetic field in the muon storage region, the former trolley system from E821 with 17 NMR probes was refurbished and upgraded with new electronics, probes and a modern motion control system. A test solenoid magnet was set up at Argonne National Laboratory for calibrating the NMR probes and the precision studies of systematic uncertainties. In this presentation, we will describe the trolley motion control scheme, the trolley position measurement methods, the electronic system for activating and reading the NMR probes and the test solenoid facility. [Preview Abstract] |
Saturday, January 28, 2017 2:54PM - 3:06PM |
C6.00008: Development and testing of fiber beam monitors for the Muon g-2 experiment Robin Bjorkquist, Edward Diamond, Benjamin Martinez, Alec Sblendorio, Frederick Gray The Muon g-2 experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 parts per billion. Careful characterization of the stored muon beam will be crucial for the experiment, because several beam-related systematic effects must be taken into account. The fiber beam monitors will provide a direct measurement of the spatial, temporal and momentum distributions and betatron oscillations of the stored muon beam. These detectors were originally built by KEK for the previous Muon g-2 experiment at Brookhaven National Lab, but have been repaired and refurbished for the upcoming experiment, including new scintillating fibers and upgraded SiPM-based readout electronics. We present the final design of the fiber beam monitor system and the results of a recent beam test performed at SLAC. [Preview Abstract] |
Saturday, January 28, 2017 3:06PM - 3:18PM |
C6.00009: Rare Eta Decays with a TPC for Optical Photons Erik Ramberg The eta meson is almost unique in the particle universe since it is a Goldstone boson and the dynamics of its decay are strongly constrained. Because the eta has no charge, decays that violate conservation laws can occur without interfering with a corresponding current. The integrated eta meson samples collected in earlier experiments have been less than $\sim$$10^8$ events, limiting considerably the search for such rare decays. A new experiment, REDTOP, is being proposed at the proton booster of Fermilab with the intent of collecting more than $10^{12}$ triggers/year for studies of rare eta decays. Such statistics are sufficient for investigating several symmetry violations, and for searches for new particles beyond the Standard Model. The physics program, the accelerators system, and the detector for REDTOP will be discussed. [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