Bulletin of the American Physical Society
2017 Fall Meeting of the APS Division of Nuclear Physics
Volume 62, Number 11
Wednesday–Saturday, October 25–28, 2017; Pittsburgh, Pennsylvania
Session HG: Mini-Symposium on Fundamental Symmetries I |
Hide Abstracts |
Chair: Nadia Fomin, University of Tennessee Room: Marquis A |
Friday, October 27, 2017 8:30AM - 9:06AM |
HG.00001: Recent Advances and Future Prospects in Fundamental Symmetries Invited Speaker: Brad Plaster A broad program of initiatives in fundamental symmetries seeks answers to several of the most pressing open questions in nuclear physics, ranging from the scale of the neutrino mass, to the particle-antiparticle nature of the neutrino, to the origin of the matter-antimatter asymmetry, to the limits of Standard Model interactions. Although the experimental program is quite broad, with efforts ranging from precision measurements of neutrino properties; to searches for electric dipole moments; to precision measurements of magnetic dipole moments; and to precision measurements of couplings, particle properties, and decays; all of these seemingly disparate initiatives are unified by several common threads. These include the use and exploitation of symmetry principles, novel cross-disciplinary experimental work at the forefront of the precision frontier, and the need for accompanying breakthroughs in development of the theory necessary for an interpretation of the anticipated results from these experiments. This talk will highlight recent accomplishments and advances in fundamental symmetries and point to the extraordinary level of ongoing activity aimed at realizing the development and interpretation of next-generation experiments. [Preview Abstract] |
Friday, October 27, 2017 9:06AM - 9:18AM |
HG.00002: Analysis of the first data from the CUORE $0\nu\beta\beta$ decay search Alexey Drobizhev CUORE---the Cryogenic Underground Observatory for Rare Events---is an experiment based at the Gran Sasso National Laboratories in Italy, searching for the neutrinoless double beta ($0\nu\beta\beta$) decay of $^{130}$Te. A ton-scale bolometer consisting of 988 5$\times$5$\times$5 cm$^3$ TeO$_2$ crystals operated at $\sim$10 mK temperatures, CUORE began taking physics data in the spring of 2017. It is expected to achieve a $9\times$10$^{25}$ year $^{130}$Te half life sensitivity (90$\%$ C.L.) after a 5 year live time. We present an analysis of early data from the experiment, focusing on spectral line shape, resolution and background performance, as well as preliminary $0\nu\beta\beta$ results. [Preview Abstract] |
Friday, October 27, 2017 9:18AM - 9:30AM |
HG.00003: Measurement of Systematic effects in the UCN\(\tau\) neutron lifetime experiment Nathan Callahan The UCN\(\tau\) experiment at the Los Alamos Neutron Science Center (LANSCe) measures the neutron \(\beta\) decay lifetime (\(\tau_n\)) by trapping Ultracold Neutrons (UCN) in a magneto-gravitational trap. UCN are confined from below by magnetic fields and above by gravity. UCN are loaded into the trap, held for times on the order of \(\tau_n\), and counted. Several systematic effects can potentially shift the measured \(\tau_n\) including heating and other losses of UCN during storage, insufficient removal of UCN with energies above the traping potential, and phase space evolution of UCN during storage which can cause changes in detection efficiency. The UCN\(\tau\) collaboration has put limits on these systematic effects via measurements in the 2016-2017 run cycle at LANSCE. For the first two effects, a limit is placed by searching for high-energy UCN at the end of storage. A limit is placed on the effects of phase space evolution by comparing arrival time distributions for UCN under different conditions. Data from the 2016-2017 run cycle and systematic limits derived from it will be discussed. [Preview Abstract] |
Friday, October 27, 2017 9:30AM - 9:42AM |
HG.00004: Status of the BL2 beam measurement of the neutron lifetime Shannon Fogwell Hoogerheide Neutron beta decay is the simplest example of nuclear beta decay and a precise value of the neutron lifetime is important for consistency tests of the Standard Model and Big Bang Nucleosynthesis models. A new measurement of the neutron lifetime, utilizing the beam method, is underway at the National Institute of Standards and Technology Center for Neutron Research with a projected uncertainty of 1 s. A review of the beam method and the technical improvements in this experiment will be presented. The status of the experiment, as well as preliminary measurements, beam characteristics, and early data will be discussed. [Preview Abstract] |
Friday, October 27, 2017 9:42AM - 9:54AM |
HG.00005: aCORN: Measuring the electron-antineutrino correlation in neutron beta decay Fred Wietfeldt The electron-antineutrino correlation ($a$-coefficient) is one of several important experimentally measured parameters of neutron beta decay. Together these parameters are used to determine the charged current weak couplings of free neutrons and protons, measure the CKM matrix element $V_{ud}$, and perform precision tests of physics beyond the Standard Model. The aCORN experiment uses a novel ``wishbone asymmetry'' method to measure the $a$-coefficient that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line obtained the result $a = -0.1090 \pm 0.0030\mbox{(stat)}\pm 0.0028\mbox{(sys)}$, the most precise measurement of the neutron $a$-coefficient to date. The second run on the new NG-C high flux beam line promises a significant improvement in precision. Details of the experiment and data analysis will be presented. [Preview Abstract] |
Friday, October 27, 2017 9:54AM - 10:06AM |
HG.00006: New Result for the $\beta$-decay Asymmetry Parameter $A_{0}$ from the UCNA Experiment M. A.-P. Brown The UCNA Experiment at the Ultracold Neutron facility at LANL uses polarized ultracold neutrons (UCN) to determine the neutron $\beta$-decay asymmetry parameter $A_0$, the angular correlation between the neutron spin and the decay electron's momentum. $A_0$ further determines $\lambda=g_A/g_V$, which, when combined with the neutron lifetime, permits extraction of the CKM matrix element $V_{ud}$ solely from neutron decay. In the UCNA experiment, UCN are produced in a pulsed, spallation driven solid deuterium source, polarized using a 7 T magnetic field, and transported through an Adiabatic Fast Passage (AFP) spin flipper prior to storage within a 1 T solenoidal spectrometer housing electron detectors at each end. The spin-flipper allows one to form a super-ratio of decay rates for neutron spins aligned parallel and anti-parallel to the 1 T magnetic field, eliminating to first order errors due to variations in the decay rate and detector efficiencies. Leading systematics and analysis techniques from the most recent analysis of data collected from 2011-2013 will be presented. [Preview Abstract] |
Friday, October 27, 2017 10:06AM - 10:18AM |
HG.00007: Penning trap mass spectrometry Q-value determinations for highly forbidden $\beta $-decays Rachel Sandler, Georg Bollen, Martin Eibach, Nadeesha Gamage, Kerim Gulyuz, Alec Hamaker, Chris Izzo, Rathnayake Kandegedara, Matt Redshaw, Ryan Ringle, Adrian Valverde, Isaac Yandow Over the last several decades, extremely sensitive, ultra-low background beta and gamma detection techniques have been developed. These techniques have enabled the observation of very rare processes, such as highly forbidden beta decays e.g. of 113Cd, 50V and 138La. Half-life measurements of highly forbidden beta decays provide a testing ground for theoretical nuclear models, and the comparison of calculated and measured energy spectra could enable a determination of the values of the weak coupling constants. Precision Q-value measurements also allow for systematic tests of the beta-particle detection techniques. We will present the results and current status of Q value determinations for highly forbidden beta decays. The Q values, the mass difference between parent and daughter nuclides, are measured using the high precision Penning trap mass spectrometer LEBIT at the National Superconducting Cyclotron Laboratory. [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