Bulletin of the American Physical Society
APS April Meeting 2018
Volume 63, Number 4
Saturday–Tuesday, April 14–17, 2018; Columbus, Ohio
Session X10: Neutrino and Nuclear Decay Rates |
Hide Abstracts |
Sponsoring Units: DNP Chair: Diana Parno, Carnegie Mellon University Room: A216 |
Tuesday, April 17, 2018 10:45AM - 10:57AM |
X10.00001: Measurement of the spectral function of Argon and Titanium through the (e,e’p) reaction Hongxia Dai In order to achieve high precision measurement in the neutrino oscillation experiments, a more accurate description of nuclear structure of targets employed in neutrino oscillation detectors is urgently needed. In the upcoming short baseline neutrino experiments at Fermilab and CERN and in the deep underground neutrino experiment (DUNE), Liquid Argon Time Projection Chambers (LArTPCs) will be used as detector technology and argon will be used as neutrino target, therefore it has become of vital importance to obtain a more reliable nuclear model capable of describing the neutrino-nucleus interaction in a wide range of kinematics. Spectral function is an example of such model and it has the potential to significantly improve the accuracy of the neutrino energy reconstruction in neutrino experiments. In light of these needs, an electron-argon experiment, E12-14-012, conducted at Jefferson Lab was recently proposed and took data in Spring 2017. The E12-14-012 collected data for (e,e’p) and (e,e’) processes, on both argon and titanium targets. In this talk we will present the latest progress on the analysis, and the first measurement of inclusive cross section of titanium and argon. [Preview Abstract] |
Tuesday, April 17, 2018 10:57AM - 11:09AM |
X10.00002: Validation of neutrino energy estimation using electron scattering data Mariana Khachatryan, Lawrence Weinstein To study neutrino oscillations, the knowledge of the initial neutrino energy is required. This energy cannot be determined directly because neutrino beams have a broad energy distribution. Instead, the initial energy is estimated from the final state particles using two main approaches. It can be determined either from the total energy of all the final state particles or, if the neutrino scatters quasi-elastically from a bound nucleon then the initial energy can be calculated approximately using the scattered angle and the energy of the outgoing charged lepton. However this is not the case in real experiments, where nuclei such as argon, iron, carbon or other heavy nuclei are used to have higher interaction rates. We have applied the methods of neutrino energy estimation to the Jefferson Lab CLAS electron scattering data and have studied how well we can reconstruct the beam energy from the scattered electron alone and from the scattered electron plus proton for a variety of targets and beam energies. [Preview Abstract] |
Tuesday, April 17, 2018 11:09AM - 11:21AM |
X10.00003: Testing a Neutrino Event Generator against Electron Scattering Data Afroditi Papadopoulou Neutrino physics is entering an age of precision measurements. A number of experiments have firmly established the existence of neutrino oscillations and determined the corresponding squared mass differences and mixing angles. These measurements have provided unambiguous evidence that neutrinos have non-vanishing masses. The large $\theta_{13}$ mixing angle will enable future experiments to search for leptonic CP violation in appearance mode, thus addressing one of the outstanding fundamental problems of particle physics. These searches will involve high precision determinations of the oscillation parameters, which in turn require a deep understanding of neutrino interactions with the atomic nuclei comprising the detectors. In view of the achieved and planned experimental accuracies, the treatment of nuclear effects is indeed regarded as one of the main sources of systematic uncertainty. In this context, a key role is played by the availability of a wealth of electron scattering data. In this analysis, data from the CLAS detector at Jefferson Lab have been used to test the accuracy of the neutrino energy reconstruction methods against the predictions of the commonly used GENIE neutrino event generator. [Preview Abstract] |
Tuesday, April 17, 2018 11:21AM - 11:33AM |
X10.00004: The ANNIE Experiment at Fermilab Emrah Tiras, Matthew Wetstein Measuring the final state neutron multiplicity from charged current neutrino-nucleus interactions is a promising method for separating between signal and background, and understanding many neutrino interaction processes. The Accelerator Neutrino Neutron Interaction Experiment (ANNIE), located at SciBooNE Hall along the Booster Neutrino Beam at Fermilab is aiming to measure neutron yield from neutrino interactions in a Gd-loaded water and deploy fast-timing and position-sensitive Large Area Picosecond Photodetectors (LAPPDs). The detector of ANNIE consists of a 23-ton water Cherenkov detector loaded with gadolinium, a muon range detector and a veto wall. ANNIE has recently completed Phase I and successfully measured background neutron events. The detector is currently undergoing an upgrade for Phase II and it will start taking data again at the end of 2018. We present the results of Phase I, the Phase II detector upgrade studies and the status of LAPPDs. [Preview Abstract] |
Tuesday, April 17, 2018 11:33AM - 11:45AM |
X10.00005: Electron Neutrino Event Selection in MicroBooNE Using Deep Learning Rui An MicroBooNE is currently the largest operational Liquid Argon Time Projection Chamber (LArTPC) worldwide. Collecting data since October 2015, the detector, with an active mass of 85 metric tons(170 tons in total) of argon, is located in the Booster Neutrino Beam(BNB) beamline at Fermilab with an oscillation baseline of 470 meters. MicroBooNE aims to measure neutrino cross sections on argon and provide a definitive investigation of the low energy excess of electron-like events observed by MiniBooNE. In this talk, we present a hybrid method of selecting low energy electron neutrino interactions utilizing aspects of traditional event selection alongside new image-processing techniques based on Deep Learning methods, such as Convolutional Neural Networks-based image classification. [Preview Abstract] |
Tuesday, April 17, 2018 11:45AM - 11:57AM |
X10.00006: Review of the Decay Rate Parameter Variation due to Neutrino/Antineutrino Interactions Shih-Chieh Liu, David Koltick, Jonathan Nistor, Jordan Heim The stability of the nuclear decay rate parameters have been investigated for many years. For example, the $^{7}$Be electron capture decay rate is affected by the electron density or low-temperature. Unexplained variations of the decay rate parameter measurement for weak interaction decays, as well as strong interaction decays, have been reported. Because the variation of the decay rate parameters have been presented by a number groups, located at various locations, using various types of detectors, different isotopes, and over extended periods of time, the nature of the variation has been questioned as not arising from ambient environmental factors but via a fundamental interaction. In this review, all the reported variations are interpreted as involving weak interaction decays and are placed into a framework as being caused by a neutrino($\nu$) or antineutrino($\bar\nu$) flux. For nuclear states with long lifetime compared to the experimental observation time, the reaction cross section is given. The resulting cross sections to alter the decay rate parameter are estimated assuming that the variations are caused by a change in the solar neutrino flux or in the case of nuclear reactor results in the difference between the reactor-on/off antineutrino flux. [Preview Abstract] |
Tuesday, April 17, 2018 11:57AM - 12:09PM |
X10.00007: Limits on the Variation of $^{54}$Mn and $^{137}$Cs Nuclear Decay Parameters due to Nuclear Reactor on-off Cycling David Koltick, Shih-Chieh Liu, Jonathan Nistor, Jordan Heim An experiment has been conducted to search for possible variation of the nuclear decay lifetime parameters in the electron capture decay of $^{54}$Mn and the beta decay of $^{137}$Cs due to an influence of the reactor $\overline{\nu}$ flux at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). The samples were exposed to approximately equal, reactor-on periods of 28 days of anti-neutrino flux at $\sim3\times10^{12}\overline{\nu}\,cm^{-2}\,sec^{-1}$ and reactor-off periods. The variation limits are set by comparing the decay rate parameters as a function of the HFIR on and off periods. Equivalent cross section limits are set on variations assuming a linear relationship between the flux exposure and the induced nuclear decay parameter variation. Measuring the decay rate requires both the detector and environment be stable over the full-time period of the experiment. A High Purity Germanium spectrometer, sensitive to radiation from 3-keV to over 3-MeV, has been built to measure radioactive decay constants to a level of 10$^{-5}\sim10^{-6}$ at a location only 6 meters from the HFIR core. Such accuracy requires an understanding of the background, signal-processing algorithms, and both the double and triple event pile-up in the observed spectrum. [Preview Abstract] |
Tuesday, April 17, 2018 12:09PM - 12:21PM |
X10.00008: Limits on Ag-108m Decay Rate Variations due to Reactor Antineutrinos Jonathan Nistor, Jordan Heim, David Koltick, Shih-Chieh Liu An experiment is currently being conducted at the High Flux Isotope Reactor (HFIR) located at Oak Ridge National Laboratory (ORNL), designed to address whether a flux of reactor-generated antineutrinos, $\overline{\nu}_e$, can alter weak interaction nuclear decay life-times. The samples are exposed to approximately equal and alternating 28-day reactor-on periods, with an antineutrino flux of $\sim 3 \times 10^{12}$ cm$^{-2}$ s$^{-1}$, and reactor-off refueling periods. Accurately measuring the radioactive decay constant in a counting experiment requires that both the detector and environment be well understood and stable over the experimental duration. A High Purity Germanium spectrometer has been constructed 6 meters from the HFIR core with the sensitivity to detect deviations in the decay rate at the level of 1 part in $10^{5}$. In the $^{108m}$Ag study, both the electron capture decay to $^{108}$Pd and the internal conversion to $^{108}$Ag are measured. The internal transition is an electromagnetic process that should remain unaffected by the antineutrino flux, and thus it presents a useful tool to further reduce systematic uncertainties. Analysis of the branching fraction of the decay modes should increase the spectrometer's sensitivity to the level of $10^{-6}$. [Preview Abstract] |
Tuesday, April 17, 2018 12:21PM - 12:33PM |
X10.00009: Muon-induced spallation backgrounds in DUNE Guanying Zhu, Shirley Li, John Beacom Galactic supernovae are rare, just a few per century, so it is important to be prepared. If we are, then the long-baseline detector DUNE could detect thousands of events, compared to the tens from SN 1987A. An important question is backgrounds from muon-induced spallation reactions. We simulate particle energy-loss processes in liquid argon, and compare relevant isotope yields with those in the water-Cherenkov detector SuperK. Our approach will help optimize the design of DUNE and further benefit the study of supernova neutrinos. [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