163 results on '"W. M. Snow"'
Search Results
2. Characterization of magnetic field noise in the ARIADNE source mass rotor
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Nancy Aggarwal, A. Schnabel, J. Voigt, Alex Brown, J. C. Long, S. Knappe-Grueneberg, W. Kilian, A. Fang, A. A. Geraci, A. Kapitulnik, D. Kim, Y. Kim, I. Lee, Y. H. Lee, C. Y. Liu, C. Lohmeyer, A. Reid, Y. Semertzidis, Y. Shin, J. Shortino, E. Smith, W. M. Snow, E. Weisman, and H. Zhang
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Physics ,QC1-999 - Abstract
The Axion Resonant Interaction Detection Experiment (ARIADNE) is a nuclear-magnetic-resonance-based experiment that will search for novel axion-induced spin-dependent interactions between an unpolarized source mass rotor and spin-polarized ^{3}He nuclei placed nearby. To detect a feeble axion-mediated signal at the subattotesla level, the experiment relies on ultralow magnetic background and noise. We measure and characterize the magnetic field from a prototype tungsten rotor. We show that the field is dominantly caused by a few discrete magnetic dipoles, likely due to impurities in the rotor. This is done via a numerical optimization pipeline which fits for the locations and magnetic moments of each dipole. We find that under the current demagnetization procedure, the magnetic moment of the impurities is bounded at 10^{−9} A m^{2}. We further show that a shielding factor of 10^{9} will support ARIADNE's design sensitivity with the current level of tungsten purity and demagnetization process.
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- 2022
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3. Neutron-state entanglement with overlapping paths
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S. J. Kuhn, S. McKay, J. Shen, N. Geerits, R. M. Dalgliesh, E. Dees, A. A. M. Irfan, F. Li, S. Lu, V. Vangelista, D. V. Baxter, G. Ortiz, S. R. Parnell, W. M. Snow, and R. Pynn
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Physics ,QC1-999 - Abstract
The development of direct probes of entanglement is integral to the rapidly expanding field of complex quantum materials. Here we test the robustness of entangled neutrons as a quantum probe by measuring the Clauser-Horne-Shimony-Holt contextuality witness while varying the beam properties. Specifically, we show that the mode entanglement of the spin and path subsystems of individual neutrons prepared in two different experiments using two different apparatuses persists even after varying the entanglement length, coherence length, and neutron energy difference of the paths. The two independent apparatuses acting as entangler-disentangler pairs are static-field magnetic Wollaston prisms and resonance-field radio-frequency flippers. Our results show that the spatial and energy properties of the neutron beam may be significantly altered without reducing the contextuality witness value below the Tsirelson bound, meaning that maximum entanglement is preserved. We also show that two paths may be considered distinguishable even when the path states significantly overlap. Therefore, we have shown that our experimental results are consistent with the distinguishable subsystem assumption down to a separation of less than 100 nm, proving entanglement and the contextual nature of reality on short length scales. This work is the key step in the realization of the modular, robust technique of entangled neutron scattering, which can extract entanglement information from a sample without the knowledge of the microscopic sample Hamiltonian: only semiquantitative knowledge of the correlation lengths of the relevant degrees of freedom and the timescales of the characteristic dynamics is required.
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- 2021
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4. High-efficiency resonant rf spin rotator with broad phase space acceptance for pulsed polarized cold neutron beams
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P.-N. Seo, L. Barrón-Palos, J. D. Bowman, T. E. Chupp, C. Crawford, M. Dabaghyan, M. Dawkins, S. J. Freedman, T. Gentile, M. T. Gericke, R. C. Gillis, G. L. Greene, F. W. Hersman, G. L. Jones, M. Kandes, S. Lamoreaux, B. Lauss, M. B. Leuschner, R. Mahurin, M. Mason, J. Mei, G. S. Mitchell, H. Nann, S. A. Page, S. I. Penttilä, W. D. Ramsay, A. Salas Bacci, S. Santra, M. Sharma, T. B. Smith, W. M. Snow, W. S. Wilburn, and H. Zhu
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation neutron beams at JSNS, LANSCE, and SNS to test the standard model and search for new physics. Certain systematic effects in some of these experiments have to be controlled at the few ppb level. The NPDGamma experiment, a search for the small parity-violating γ-ray asymmetry A_{γ} in polarized cold neutron capture on parahydrogen, is one example. For the NPDGamma experiment we developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm×9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to rf neutron spin flippers based on adiabatic fast passage. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically polarized ^{3}He neutron spin filters. The efficiency of the spin rotator was measured at LANSCE to be 98.8±0.5% for neutron energies from 3 to 20 meV over the full phase space of the beam. Systematic effects that the rf spin rotator introduces to the NPDGamma experiment are considered.
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- 2008
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5. Angular distribution of γ rays from a neutron-induced p -wave resonance of Xe132
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T. Okudaira, Y. Tani, S. Endo, J. Doskow, H. Fujioka, K. Hirota, K. Kameda, A. Kimura, M. Kitaguchi, M. Luxnat, K. Sakai, D. C. Schaper, T. Shima, H. M. Shimizu, W. M. Snow, S. Takada, T. Yamamoto, H. Yoshikawa, and T. Yoshioka
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- 2023
6. COHERENT constraint on leptophobic dark matter using CsI data
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D. Akimov, P. An, C. Awe, P. S. Barbeau, B. Becker, V. Belov, I. Bernardi, M. A. Blackston, C. Bock, A. Bolozdynya, R. Bouabid, J. Browning, B. Cabrera-Palmer, D. Chernyak, E. Conley, J. Daughhetee, J. Detwiler, K. Ding, M. R. Durand, Y. Efremenko, S. R. Elliott, L. Fabris, M. Febbraro, A. Gallo Rosso, A. Galindo-Uribarri, M. P. Green, M. R. Heath, S. Hedges, D. Hoang, M. Hughes, B. A. Johnson, T. Johnson, A. Khromov, A. Konovalov, E. Kozlova, A. Kumpan, L. Li, J. M. Link, J. Liu, A. Major, K. Mann, D. M. Markoff, J. Mastroberti, J. Mattingly, P. E. Mueller, J. Newby, D. S. Parno, S. I. Penttila, D. Pershey, C. Prior, R. Rapp, H. Ray, O. Razuvaeva, D. Reyna, G. C. Rich, J. Ross, D. Rudik, J. Runge, D. J. Salvat, A. M. Salyapongse, J. Sander, K. Scholberg, A. Shakirov, G. Simakov, W. M. Snow, V. Sosnovstsev, B. Suh, R. Tayloe, K. Tellez-Giron-Flores, I. Tolstukhin, E. Ujah, J. Vanderwerp, R. L. Varner, C. J. Virtue, G. Visser, T. Wongjirad, Y.-R. Yen, J. Yoo, C.-H. Yu, and J. Zettlemoyer
- Abstract
We use data from the COHERENT CsI[Na] scintillation detector to constrain sub-GeV leptophobic dark matter models. This detector was built to observe low-energy nuclear recoils from coherent elastic neutrino-nucleus scattering. These capabilities enable searches for dark matter particles produced at the Spallation Neutron Source mediated by a vector portal particle with masses between 2 and 400 MeV/c2. No evidence for dark matter is observed and a limit on the mediator coupling to quarks is placed. This constraint improves upon previous results by two orders of magnitude. This newly explored parameter space probes the region where the dark matter relic abundance is explained by leptophobic dark matter when the mediator mass is roughly twice the dark matter mass. COHERENT sets the best constraint on leptophobic dark matter at these masses.
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- 2022
7. Imaging of PbWO4 Crystals for G Experiment Test Masses Using a Laser Interferometer
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K T A Assumin-Gyimah, M G Holt, D Dutta, and W M Snow
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Physics - Instrumentation and Detectors ,Physics and Astronomy (miscellaneous) ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,General Relativity and Quantum Cosmology (gr-qc) ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,General Relativity and Quantum Cosmology - Abstract
It is highly desirable for future measurements of Newton's gravitational constant $G$ to use test/source masses that allow nondestructive, quantitative internal density gradient measurements. High density optically transparent materials are ideally suited for this purpose since their density gradient can be measured with laser interferometry, and they allow in-situ optical metrology methods for the critical distance measurements often needed in a $G$ apparatus. We present an upper bound on possible internal density gradients in lead tungstate (PbWO$_4$) crystals determined using a laser interferometer. We placed an upper bound on the fractional atomic density gradient in two PbWO$_4$ test crystals of ${1 \over \rho}{d\rho \over dx}, Comment: 8 pages, 5 figures, submitted to Classical and Quantum Gravity. arXiv admin note: substantial text overlap with arXiv:2109.14008
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- 2022
8. Neutron phase contrast imaging of PbWO4 crystals for G experiment test masses using a Talbot-Lau neutron interferometer
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K T A Assumin-Gyimah, D Dutta, D S Hussey, W M Snow, C Langlois, and V Lee
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Condensed Matter - Materials Science ,Physics - Instrumentation and Detectors ,Physics and Astronomy (miscellaneous) ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,General Relativity and Quantum Cosmology (gr-qc) ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,General Relativity and Quantum Cosmology - Abstract
The use of transparent test/source masses can benefit future measurements of Newton's gravitational constant $G$. Such transparent test mass materials can enable nondestructive, quantitative internal density gradient measurements using optical interferometry and allow in-situ optical metrology methods to be realized for the critical distance measurements often needed in a $G$ apparatus. To confirm the sensitivity of such optical interferometry measurements to internal density gradients it is desirable to conduct a check with a totally independent technique. We present an upper bound on possible internal density gradients in lead tungstate (PbWO$_4$) crystals using a Talbot-Lau neutron interferometer on the Cold Neutron Imaging Facility (CNIF) at NIST. We placed an upper bound on a fractional atomic density gradient in two PbWO$_{4}$ test crystals of ${1 \over N}{dN \over dx}, 10 pages, 8 figures, submitted to Classical and Quantum Gravity
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- 2022
9. Proof-of-principle Experiment for the Study of a New Intermediate-range Interaction Using Coherent Neutron Scattering
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Katsuya Hirota, Masayuki Hiromoto, Tamaki Yoshioka, Shuhei Hara, W. M. Snow, Tatsushi Shima, Ryota Kondo, Noriko Oi, Masaaki Kitaguchi, Kenji Mishima, Taichi Hori, Hirohiko M. Shimizu, Rintaro Nakabe, Christopher C. Haddock, and Takashi Ino
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Physics ,Range (particle radiation) ,Proof of concept ,Neutron scattering ,Computational physics - Published
- 2021
10. New high-sensitivity searches for neutrons converting into antineutrons and/or sterile neutrons at the HIBEAM/NNBAR experiment at the European Spallation Source
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J. I. Marquez, E. Golubeva, Zurab Berezhiani, B. Z. Kopeliovich, K. Dunne, M. Lindroos, L. Townsend, Takeyasu M. Ito, Agneta Oskarsson, A. Kozela, David Milstead, Samuel Silverstein, D. D. DiJulio, S. Yiu, A. D. Dolgov, Lawrence Heilbronn, P. Fierlinger, A. Tureanu, Christian Bohm, G. Ichikawa, B. Rybolt, E. B. Klinkby, Igor Tkachev, Arkady Vainshtein, Y. N. Pokotilovski, Archil Kobakhidze, Kevin W. Anderson, R. W. Pattie, Y. J. Jwa, Leah Broussard, R. Biondi, B. Kerbikov, David V. Baxter, J. Cedercäll, David Olle Rickard Silvermyr, A. Holley, A. Addazi, A. P. Serebrov, Hans P. Mumm, S. Girmohanta, V. Santoro, Arthur E. Ruggles, P. Geltenbort, Yuri Kamyshkov, H. M. Shimizu, Geoffrey Greene, N. Rizzi, Joshua Barrow, A. Takibayev, Christopher Crawford, T. Greenshaw, N. Rossi, E. Paryev, Thomas Nilsson, A. A. Nepomuceno, Robert Shrock, L. W. Koerner, R. Woracek, T. Johansson, S. Gardiner, L. Varriano, G. Muhrer, Susan Gardner, A. Kupsc, J. M. Richard, Bernhard Meirose, R. Hall-Wilton, Vladimir Gudkov, T. Morishima, J. Makkinje, E. Rinaldi, J. Herrero-Garcia, Michael R. Fitzsimmons, P. S. B. Dev, Y. T. Lee, Erik B. Iverson, K. S. Babu, Y. Yamagata, C. Redding, H. Perrey, Rabindra N. Mohapatra, Albert Young, V. V. Nesvizhevsky, Masaaki Kitaguchi, S. Penttil, G. Brooijmans, Fabrizio Nesti, J. de Vries, Riccardo Bevilacqua, O. Zimmer, Kalliopi Kanaki, Robert Wagner, K. Ramic, E. Kearns, Z. Zhang, K. Nagamoto, L. Zanini, S. Ansell, P. M. Bentley, T. Kittelmann, A. Fomin, T. M. Miller, U. Sarkar, Goran Senjanovic, A. Galindo-Uribarri, W. M. Snow, Pavel Golubev, V. A. Kudryavtsev, M. J. Frost, Z. Kokai, A. Saunders, L. Jönsson, D. Ries, I. Potashnikovav, Institut Laue-Langevin (ILL), ILL, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), and Department of Physics
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baryon number violation ,feebly interacting particles ,European Spallation Source ,baryogenesis ,Physics beyond the Standard Model ,Nuclear Theory ,EXPERIMENTAL LIMIT ,Antineutron ,01 natural sciences ,Subatomär fysik ,ANTIPROTON ANNIHILATION ,n: oscillation ,Subatomic Physics ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,Nuclear Experiment ,sterile ,Physics ,MIRROR MATTER ,new physics ,anti-n ,ddc ,Antimatter ,baryon: asymmetry ,proposed experiment ,DAMA ANNUAL MODULATION ,Nuclear and High Energy Physics ,Particle physics ,Accelerator Physics and Instrumentation ,114 Physical sciences ,Baryon asymmetry ,nuclear physics ,0103 physical sciences ,DARK-MATTER ,mixing ,Neutron ,Sensitivity (control systems) ,[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det] ,TRANSITION OPERATORS ,010306 general physics ,baryon number: violation ,activity report ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Acceleratorfysik och instrumentering ,MAJORANA NEUTRINOS ,sensitivity ,Baryogenesis ,regeneration ,UNIFIED PICTURE ,B-L SYMMETRY ,Baryon number ,BARYON-NUMBER NONCONSERVATION - Abstract
The violation of baryon number, B , is an essential ingredient for the preferential creation of matter over antimatter needed to account for the observed baryon asymmetry in the Universe. However, such a process has yet to be experimentally observed. The HIBEAM/NNBAR program is a proposed two-stage experiment at the European Spallation Source to search for baryon number violation. The program will include high-sensitivity searches for processes that violate baryon number by one or two units: free neutron–antineutron oscillation ( n → n ̄ ) via mixing, neutron–antineutron oscillation via regeneration from a sterile neutron state ( n → [ n ′ , n ̄ ′ ] → n ̄ ), and neutron disappearance (n → n′); the effective Δ B = 0 process of neutron regeneration ( n → [ n ′ , n ̄ ′ ] → n ) is also possible. The program can be used to discover and characterize mixing in the neutron, antineutron and sterile neutron sectors. The experiment addresses topical open questions such as the origins of baryogenesis and the nature of dark matter, and is sensitive to scales of new physics substantially in excess of those available at colliders. A goal of the program is to open a discovery window to neutron conversion probabilities (sensitivities) by up to three orders of magnitude compared with previous searches. The opportunity to make such a leap in sensitivity tests should not be squandered. The experiment pulls together a diverse international team of physicists from the particle (collider and low energy) and nuclear physics communities, while also including specialists in neutronics and magnetics.
- Published
- 2021
11. A D$_{2}$O detector for flux normalization of a pion decay-at-rest neutrino source
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G.C. Rich, R. Rapp, J. Daughhetee, D Hoang, G. Sinev, C. J. Virtue, A. Gallo Rosso, S. R. Elliott, Seppo Penttila, K. Mann, T. Wongjirad, M.R. Heath, P. S. Barbeau, P. An, J Ross, Kate Scholberg, S. Hedges, V. Sosnovstsev, A. V. Kumpan, Belkis Cabrera-Palmer, Diana Parno, D. Akimov, E. Day, E. Conley, J Mastroberti, I. Bernardi, P. E. Mueller, W. M. Snow, E.M. Ward, Michael Febbraro, E Ujah, A.V. Khromov, J. Zettlemoyer, Gerard Visser, V. Belov, E. S. Kozlova, Matthew A Blackston, J. Koros, O. Razuvaeva, J. M. Link, J. Vanderwerp, B. Becker, C.-H. Yu, K. Tellez-Giron-Flores, D. M. Markoff, A. Konovalov, H. Ray, Yu. Efremenko, B. Suh, A. Galindo-Uribarri, Lorenzo Fabris, AM Salyapongse, Tyler Johnson, C. Wiseman, J. Runge, D.J. Salvat, C. Awe, A. Shakirov, Rex Tayloe, G. Simakov, Liang Li, Jing Liu, D. Rudik, J. A. Detwiler, Jason Newby, J. Raybern, Y.-R. Yen, K Ding, D. Pershey, M.R. Durand, M. P. Green, Alexander Bolozdynya, R. L. Varner, Jaeun Yoo, I. Tolstukhin, D. Chernyak, David Reyna, and M. Hughes
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Physics ,Physics - Instrumentation and Detectors ,Physics::Instrumentation and Detectors ,Physics beyond the Standard Model ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Flux ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,Oak Ridge National Laboratory ,High Energy Physics - Experiment ,Nuclear physics ,High Energy Physics - Experiment (hep-ex) ,Pion ,Neutrino detector ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,Neutrino ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,Instrumentation ,Mathematical Physics ,Spallation Neutron Source - Abstract
We report on the technical design and expected performance of a 592 kg heavy-water-Cherenkov detector to measure the absolute neutrino flux from the pion-decay-at-rest neutrino source at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The detector will be located roughly 20 m from the SNS target and will measure the neutrino flux with better than 5% statistical uncertainty in 2 years. This heavy-water detector will serve as the first module of a two-module detector system to ultimately measure the neutrino flux to 2-3% at both the First Target Station and the planned Second Target Station of the SNS. This detector will significantly reduce a dominant systematic uncertainty for neutrino cross-section measurements at the SNS, increasing the sensitivity of searches for new physics., Comment: As accepted to JINST
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- 2021
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12. Search for exotic spin-dependent couplings of the neutron with matter using spin-echo based neutron interferometry
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Robert M. Dalgliesh, K. E. Steffen, Jeroen Plomp, Joshaniel F. K. Cooper, Niels Geerits, W. M. Snow, Nina-Juliane Steinke, Steven R. Parnell, V.O. de Haan, and A.A. van Well
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Physics ,Particle physics ,010308 nuclear & particles physics ,Physics beyond the Standard Model ,Electron ,01 natural sciences ,Vector boson ,0103 physical sciences ,Neutron ,010306 general physics ,Nucleon ,Pseudovector ,Boson ,Spin-½ - Abstract
Various theories beyond the Standard Model predict new particles with masses in the sub-eV range with very weak couplings to ordinary matter which can possess spin-dependent couplings to electrons and nucleons. We report null results of a search for possible exotic spin-dependent couplings of the neutron which could be induced by the exchange of light weakly coupled bosons or spin-gravity coupling conducted using a spin-echo neutron spectrometer. We constrain the products ${g}_{A}^{2}$ and ${g}_{A}{g}_{V}$ of the axial vector coupling of the neutron to the matter of the Earth through the exchange of a weakly coupled vector boson for force ranges between the metre scale and the radius of the Earth. We also constrain the constants in some theories of exotic spin-gravity couplings.
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- 2020
13. Experimental Apparatus and Design for Parity-Odd Asymmetry Measurements in Compound Nuclei
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Brad Plaster, Gerard Visser, Hirohiko M. Shimizu, A. Martin, L. Barrón-Palos, Seppo Penttila, L. Cole, Danielle Schaper, J. Doskow, Christopher Crawford, T. Yamamoto, W. M. Snow, C.J. Auton, Jonathan Curole, P. M. King, D. Olivera, G. Forbes, J. Vanderwerp, H. Lu, D. Hajer, and M. Gabel
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Physics ,Particle physics ,media_common.quotation_subject ,Parity (physics) ,Asymmetry ,media_common - Published
- 2020
14. Exotic Spin-Dependent Interaction Searches at Indiana University
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W. M. Snow, Chen-Yu Liu, J. Shortino, M. Gabel, E. Smith, A. Din, S. Reger, Janet C. Long, J. Biermen, E. Guess, M. Zhang, B. Short, M. Severinov, A. Reid, I. Lee, and A. Grossman
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Physics ,Particle physics ,Physics beyond the Standard Model ,High Energy Physics::Phenomenology ,Dark matter ,Particle ,Strong CP problem ,Axion ,Spin-½ ,Boson - Abstract
The axion is a hypothesized particle appearing in various theories beyond the Standard Model. It is a light spin-0 boson initially postulated to solve the strong CP problem and is also a strong candidate for dark matter. If the axion or an axion-like particle exists, it would mediate a P-odd and T-odd spin-dependent interaction. We describe two experiments under development at Indiana University-Bloomington to search for such an interaction.
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- 2020
15. Comment on B.O. Kerbikov, 'The effect of collisions with the wall on neutron-antineutron transitions', Phys. Lett. B 795 (2019) 362
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K.V. Protasov, Valery Nesvizhevsky, W. M. Snow, A. Yu. Voronin, V. Gudkov, Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
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Physics ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,scattering ,Antineutron ,sensitivity ,01 natural sciences ,lcsh:QC1-999 ,Nuclear physics ,n anti-n: transition ,[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] ,0103 physical sciences ,Neutron ,010306 general physics ,n anti-n: oscillation ,ComputingMilieux_MISCELLANEOUS ,lcsh:Physics - Abstract
International audience
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- 2020
16. Internal consistency of neutron coherent scattering length measurements from neutron interferometry and from neutron gravity reflectometry
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J. Apanavicius, E. Alexeev, A. Reid, M. Peters, J. S. Devaney, W. M. Snow, B. Shen, K. A. Dickerson, J. Woo, Christopher C. Haddock, and H. Drabek
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Physics ,Particle physics ,010308 nuclear & particles physics ,Scattering ,Yukawa potential ,Scattering length ,Neutron scattering ,Lambda ,01 natural sciences ,Scattering amplitude ,Gravitational potential ,0103 physical sciences ,Neutron ,010306 general physics - Abstract
Many theories beyond the Standard Model postulate short-range modifications to gravity which produce deviations of Newton's gravitational potential from a strict $1/r$ dependence. It is common to analyze experiments searching for these modifications using a potential of the form ${V}^{\ensuremath{'}}(r)=\phantom{\rule{0ex}{0ex}}\ensuremath{-}\frac{GMm}{r}[1+\ensuremath{\alpha}\mathrm{exp}(\ensuremath{-}r/\ensuremath{\lambda})]$. The best present constraints on $\ensuremath{\alpha}$ for $\ensuremath{\lambda}l100\text{ }\text{ }\mathrm{nm}$ come from neutron scattering and often employ comparisons of different measurements of the coherent neutron scattering amplitudes $b$. We analyze the internal consistency of existing data from two different types of measurements of low-energy neutron scattering amplitudes: neutron interferometry, which involves squared momentum transfers ${q}^{2}=0$, and neutron gravity reflectometry, which involves squared momentum transfers ${q}^{2}=8m{V}_{\mathrm{opt}}$ where $m$ is the neutron mass and ${V}_{\mathrm{opt}}$ is the neutron optical potential of the medium. We show that the fractional difference $\frac{\mathrm{\ensuremath{\Delta}}b}{|b|}$ averaged over the seven elements where high precision data exist on the same material from both measurement methods is $[2.2\ifmmode\pm\else\textpm\fi{}1.4]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. We also show that $\frac{\mathrm{\ensuremath{\Delta}}b}{|b|}$ for these data is insensitive both to exotic Yukawa interactions and also to the electromagnetic neutron-atom interactions proportional to the neutron-electron scattering length ${b}_{ne}$ and the neutron polarizability scattering amplitude ${b}_{\mathrm{pol}}$. This result will be useful in any future global analyses of neutron scattering data to determine ${b}_{ne}$ and bound $\ensuremath{\alpha}$ and $\ensuremath{\lambda}$. We also discuss how various neutron interferometric and scattering techniques with cold and ultracold neutrons can be used to improve the precision of $b$ measurements and make some specific proposals.
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- 2020
17. First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon
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D. Rudik, T. Wongjirad, J. Raybern, J. T. Librande, Belkis Cabrera-Palmer, Y.-R. Yen, J. Yoo, C. J. Virtue, G.C. Rich, S. I. Penttilä, D. Chernyak, D. C. Radford, M. P. Green, A. Kumpan, A. Konovalov, Yu. Efremenko, Kathryn Mann, P. S. Barbeau, M. del Valle Coello, B. Suh, David Reyna, E. Kozlova, R. L. Cooper, J. M. Link, B. Becker, A. Shakirov, M.R. Heath, Gerard Visser, Rex Tayloe, J. B. Albert, J. Daughhetee, D. M. Markoff, C.-H. Yu, M. Hughes, D. Akimov, V. Belov, Diana Parno, O. Razuvaeva, I. Bernardi, J. A. Detwiler, Jason Newby, L. Blokland, Tyler Johnson, R. L. Varner, H. Ray, G. Sinev, Alexander Bolozdynya, W. Fox, A. Khromov, K. S. Hansen, Liang Li, S. Hedges, J. Yang, P. An, E. Conley, R. T. Thornton, C. Wiseman, K. Tellez-Giron-Flores, Lorenzo Fabris, C. Awe, Jing Liu, Michael Febbraro, D. Pershey, W. M. Snow, Matthew A Blackston, H. Moreno, A. Galindo-Uribarri, V. Sosnovtsev, O. McGoldrick, Kate Scholberg, J. Zettlemoyer, J. Runge, M.R. Durand, D.J. Salvat, N. Chen, P. E. Mueller, J. Vanderwerp, M. Kaemingk, L. J. Kaufman, S. R. Elliott, G. Simakov, I. Tolstukhin, R. Rapp, and A. Gallo Rosso
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Physics ,Argon ,Scattering ,Physics::Instrumentation and Detectors ,Detector ,FOS: Physical sciences ,General Physics and Astronomy ,Flux ,chemistry.chemical_element ,01 natural sciences ,Standard Model ,High Energy Physics - Experiment ,Nuclear physics ,High Energy Physics - Experiment (hep-ex) ,Cross section (physics) ,chemistry ,0103 physical sciences ,Nuclear Experiment (nucl-ex) ,Neutrino ,010306 general physics ,Nuclear Experiment ,Spallation Neutron Source - Abstract
We report the first measurement of coherent elastic neutrino-nucleus scattering (\cevns) on argon using a liquid argon detector at the Oak Ridge National Laboratory Spallation Neutron Source. Two independent analyses prefer \cevns over the background-only null hypothesis with greater than $3\sigma$ significance. The measured cross section, averaged over the incident neutrino flux, is (2.2 $\pm$ 0.7) $\times$10$^{-39}$ cm$^2$ -- consistent with the standard model prediction. The neutron-number dependence of this result, together with that from our previous measurement on CsI, confirms the existence of the \cevns process and provides improved constraints on non-standard neutrino interactions., Comment: 8 pages, 5 figures with 2 pages, 6 figures supplementary material V3: fixes to figs 3,4 V4: fix typo in table 1, V5: replaced missing appendix, V6: fix Eq 1, new fig 3, V7 final version, updated with final revisions
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- 2020
18. Development of a $^{83\mathrm{m}}$Kr source for the calibration of the CENNS-10 Liquid Argon Detector
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K. Mann, Michael Febbraro, Matthew A Blackston, V.V. Sosnovtsev, A. Shakirov, J. Daughhetee, A.V. Khromov, R. T. Thornton, L. Blokland, Liang Li, O. Razuvaeva, P. An, D. M. Markoff, S. Hedges, C.-H. Yu, P. E. Mueller, J. Zettlemoyer, G. Simakov, R. L. Varner, J. Vanderwerp, N. Chen, Seppo Penttila, T. Wongjirad, Gerard Visser, Alexander Bolozdynya, M.R. Heath, W. M. Snow, R. Venkataraman, D. G. Rudik, A. V. Kumpan, S. R. Elliott, Lorenzo Fabris, Kate Scholberg, Diana Parno, J. Runge, C. J. Virtue, A. Galindo-Uribarri, G.C. Rich, I. Bernardi, E. S. Kozlova, V. Belov, Belkis Cabrera-Palmer, A. Konovalov, Yu. Efremenko, O. McGoldrick, Tyler Johnson, D.J. Salvat, H. Ray, E. Conley, B. Suh, C. Wiseman, D. C. Radford, G. Sinev, J. Raybern, Jaeun Yoo, K. S. Hansen, I. Tolstukhin, Y.-R. Yen, J. Yang, M. del Valle Coello, D. Chernyak, David Reyna, Rex Tayloe, M. Hughes, P. S. Barbeau, M. P. Green, W. Fox, J. T. Librande, J. M. Link, B. Becker, J. A. Detwiler, K. Tellez-Giron-Flores, Jason Newby, A. Gallo Rosso, R. Rapp, D. Akimov, D. Pershey, M.R. Durand, C. Awe, and Jing Liu
- Subjects
Materials science ,Physics - Instrumentation and Detectors ,business.industry ,Physics::Instrumentation and Detectors ,Detector ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,Optics ,Double phase ,Neutrino detector ,Ionization ,Liquid argon ,Calibration ,High Energy Physics::Experiment ,Nuclear Experiment (nucl-ex) ,business ,Instrumentation ,Nuclear Experiment ,Mathematical Physics - Abstract
We report on the preparation of and calibration measurements with a $^{83\mathrm{m}}$Kr source for the CENNS-10 liquid argon detector. $^{83\mathrm{m}}$Kr atoms generated in the decay of a $^{83}$Rb source were introduced into the detector via injection into the Ar circulation loop. Scintillation light arising from the 9.4 keV and 32.1 keV conversion electrons in the decay of $^{83\mathrm{m}}$Kr in the detector volume were then observed. This calibration source allows the characterization of the low-energy response of the CENNS-10 detector and is applicable to other low-energy-threshold detectors. The energy resolution of the detector was measured to be 9$\%$ at the total $^{83\mathrm{m}}$Kr decay energy of 41.5 keV. We performed an analysis to separately calibrate the detector using the two conversion electrons at 9.4 keV and 32.1 keV, Comment: v2: As accepted to JINST
- Published
- 2020
- Full Text
- View/download PDF
19. A modular apparatus for use in high-precision measurements of parity violation in polarized eV neutron transmission'
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P. M. King, W. M. Snow, L. Barrón-Palos, Gerard Visser, K. Steffen, B. Short, H. Dhahri, M. Borrego, Ángel M Chávez, K. Knickerbocker, C.J. Auton, Seppo Penttila, J. Doskow, Christopher Crawford, Boyd M. Goodson, A. Pérez-Martín, D. Olivera-Velarde, Danielle Schaper, M.H. Gervais, L. Cole, Chenyang Jiang, J. Curole, J.G. Otero Munoz, Michal Mocko, J. Vanderwerp, W. Fox, K.A. Dickerson, and H. Lu
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Nuclear and High Energy Physics ,Physics - Instrumentation and Detectors ,media_common.quotation_subject ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,FOS: Physical sciences ,Scintillator ,01 natural sciences ,Asymmetry ,Nuclear physics ,Optical pumping ,0103 physical sciences ,Neutron ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Instrumentation ,media_common ,Physics ,010308 nuclear & particles physics ,Scattering ,Resonance ,Instrumentation and Detectors (physics.ins-det) ,Polarization (waves) ,Ionization chamber - Abstract
We describe a modular apparatus for use in parity-violation measurements in epithermal neutron-nucleus resonances with high instantaneous neutron fluxes at the Manuel Lujan Jr.\ Neutron Scattering Center at Los Alamos National Laboratory. This apparatus is designed to conduct high-precision measurements of the parity-odd transmission asymmetry of longitudinally polarized neutrons through targets containing nuclei with p-wave neutron-nucleus resonances in the 0.1-10 eV energy regime and to accommodate a future search for time reversal violation in polarized neutron transmission through polarized nuclear targets. The apparatus consists of an adjustable neutron and gamma collimation system, a \(^3\)He-$^{4}$He ion chamber neutron flux monitor, two identical cryostats for target cooling, an adiabatic eV-neutron spin flipper, a near-unit efficiency \(^6\)Li-\(^{7}\)Li scintillation detector operated in current mode, a flexible CAEN data acquisition system, and a neutron spin filter based on spin-exchange optical pumping of $^{3}$He gas. We describe the features of the apparatus design devoted to the suppression of systematic errors in parity-odd asymmetry measurements. We describe the configuration of the apparatus used to conduct a precision measurement of parity violation at the 0.7 eV p-wave resonance in $^{139}$La which employs two identical $^{139}$La targets, one to polarize the beam on the p-wave resonance using the weak interaction and one to analyze the polarization., Comment: 43 pages, 23 figures
- Published
- 2020
- Full Text
- View/download PDF
20. Source Mass Characterization in the ARIADNE Axion Experiment
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Dongok Kim, Chen-Yu Liu, Yun Chang Shin, Jens-Uwe Voigt, Evan Weisman, Andrew Geraci, Aharon Kapitulnik, Allard Schnabel, Chloe Lohmeyer, Nancy Aggarwal, Younggeun Kim, Lutz Trahms, Alex Brown, Y. H. Lee, W. M. Snow, Yannis K. Semertzidis, Asimina Arvanitaki, Samuel Mumford, J. Shortino, Alan Fang, Edward Smith, I. Lee, Eli Levenson-Falk, A. Reid, and Janet C. Long
- Subjects
Physics ,Superconductivity ,Physics::Instrumentation and Detectors ,010308 nuclear & particles physics ,Johnson–Nyquist noise ,01 natural sciences ,7. Clean energy ,law.invention ,Nuclear physics ,SQUID ,Magnetization ,law ,0103 physical sciences ,Electromagnetic shielding ,010306 general physics ,Axion ,Noise (radio) ,Magnetic impurity - Abstract
The Axion Resonant InterAction Detection Experiment (ARIADNE) is a collaborative effort to search for the QCD axion using nuclear magnetic resonance (NMR), where the axion acts as a mediator of spin-dependent forces between an unpolarized tungsten source mass and a sample of polarized helium-3 gas. Since the experiment involves precision measurement of a small magnetization, it relies on limiting ordinary magnetic noise with superconducting magnetic shielding. In addition to the shielding, proper characterization of the noise level from other sources is crucial. We investigate one such noise source in detail: the magnetic noise due to impurities and Johnson noise in the tungsten source mass.
- Published
- 2020
21. Microwave Cavities and Detectors for Axion Research
- Author
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Josh Long, Alex Brown, Chloe Lohmeyer, Eric Smith, Nancy Aggarwal, W. M. Snow, Aharon Kapitulnik, Eli Levenson-Falk, A. Reid, Jens Voigt, Yannis K. Semertzidis, Chen-Yu Liu, Alan Fang, Yong Ho Lee, Evan Weisman, Lutz Trahms, Samuel Mumford, J. Shortino, Inbum Lee, Allard Schnabel, Younggeun Kim, Andrew Geraci, Asimina Arvanitaki, Dongok Kim, and Yun Shin
- Subjects
Quantum chromodynamics ,Physics ,Superconductivity ,Physics::Instrumentation and Detectors ,010308 nuclear & particles physics ,chemistry.chemical_element ,Johnson–Nyquist noise ,Tungsten ,01 natural sciences ,Nuclear physics ,Magnetization ,chemistry ,0103 physical sciences ,Electromagnetic shielding ,010306 general physics ,Axion ,Noise (radio) - Abstract
The Axion Resonant InterAction Detection Experiment (ARIADNE) is a collaborative effort to search for the QCD axion using nuclear magnetic resonance (NMR), where the axion acts as a mediator of spin-dependent forces between an unpolarized tungsten source mass and a sample of polarized helium-3 gas. Since the experiment involves precision measurement of a small magnetization, it relies on limiting ordinary magnetic noise with superconducting magnetic shielding. In addition to the shielding, proper characterization of the noise level from other sources is crucial. We investigate one such noise source in detail: the magnetic noise due to impurities and Johnson noise in the tungsten source mass.
- Published
- 2020
22. Precision determination of absolute neutron flux
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G. L. Greene, Maynard S. Dewey, A. Yue, E. Anderson, David M. Gilliam, A. Laptev, W. M. Snow, and Jeffrey S. Nico
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Physics ,Physics - Instrumentation and Detectors ,Neutron monitor ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,General Engineering ,Gamma ray ,FOS: Physical sciences ,Bragg's law ,Instrumentation and Detectors (physics.ins-det) ,Neutron radiation ,01 natural sciences ,7. Clean energy ,Article ,Nuclear physics ,Neutron capture ,Neutron flux ,0103 physical sciences ,Neutron cross section ,Neutron ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,010306 general physics - Abstract
A technique for establishing the total neutron rate of a highly-collimated monochromatic cold neutron beam was demonstrated using a method of an alpha-gamma counter. The method involves only the counting of measured rates and is independent of neutron cross sections, decay chain branching ratios, and neutron beam energy. For the measurement, a target of 10B-enriched boron carbide totally absorbed the neutrons in a monochromatic beam, and the rate of absorbed neutrons was determined by counting 478keV gamma rays from neutron capture on 10B with calibrated high-purity germanium detectors. A second measurement based on Bragg diffraction from a perfect silicon crystal was performed to determine the mean de Broglie wavelength of the beam to a precision of 0.024 %. With these measurements, the detection efficiency of a neutron monitor based on neutron absorption on 6Li was determined to an overall uncertainty of 0.058 %. We discuss the principle of the alpha-gamma method and present details of how the measurement was performed including the systematic effects. We also describe how this method may be used for applications in neutron dosimetry and metrology, fundamental neutron physics, and neutron cross section measurements., Comment: 44 pages
- Published
- 2018
23. Slotted rotatable target assembly and systematic error analysis for a search for long range spin dependent interactions from exotic vector boson exchange using neutron spin rotation
- Author
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Christopher C. Haddock, W. Fox, A. T. Holley, Bret E. Crawford, M. Sarsour, Scott W. Magers, J. Vanderwerp, I. Francis, and W. M. Snow
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Physics ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,Neutron radiation ,Rotation ,01 natural sciences ,Magnetic field ,Computational physics ,Vector boson ,0103 physical sciences ,Atom ,Neutron ,010306 general physics ,Instrumentation ,Beam (structure) ,Spin-½ - Abstract
We discuss the design and construction of a novel target array of nonmagnetic test masses used in a neutron polarimetry measurement made in search for new possible exotic spin dependent neutron–atominteractions of Nature at sub-mm length scales. This target was designed to accept and efficiently transmit a transversely polarized slow neutron beam through a series of long open parallel slots bounded by flat rectangular plates. These openings possessed equal atom density gradients normal to the slots from the flat test masses with dimensions optimized to achieve maximum sensitivity to an exotic spin-dependent interaction from vector boson exchanges with ranges in the mm - μ m regime. The parallel slots were oriented differently in four quadrants that can be rotated about the neutron beam axis in discrete 90°increments using a Geneva drive. The spin rotation signals from the 4 quadrants were measured using a segmented neutron ion chamber to suppress possible systematic errors from stray magnetic fields in the target region. We discuss the per-neutron sensitivity of the target to the exotic interaction, the design constraints, the potential sources of systematic errors which could be present in this design, and our estimate of the achievable sensitivity using this method.
- Published
- 2018
24. Precision neutron flux measurement using the Alpha-Gamma device
- Author
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Geoffrey Greene, Hans P. Mumm, Nadia Fomin, W. M. Snow, Evan R. Adamek, Jeffrey S. Nico, Shannon Fogwell Hoogerheide, David M. Gilliam, and Maynard S. Dewey
- Subjects
Physics ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,QC1-999 ,chemistry.chemical_element ,Germanium ,Neutron radiation ,01 natural sciences ,Nuclear physics ,Cross section (physics) ,Neutron capture ,chemistry ,Neutron flux ,0103 physical sciences ,NIST ,Neutron ,010306 general physics ,Boron ,Nuclear Experiment - Abstract
The Alpha-Gamma device at the National Institute of Standards and Technology (NIST) utilizes neutron capture on a totally absorbing 10B deposit to measure the absolute neutron flux of a monochromatic cold neutron beam. Gammas produced by the boron capture are counted using high purity germanium detectors, which are calibrated using a well-measured 239Pu alpha source and the alpha-to-gamma ratio from neutron capture on a thin 10B target. This device has been successfully operated and used to calibrate the neutron flux monitor for the BL2 neutron lifetime experiment at NIST. It is also being used for a measurement of the 6Li(n,t)4He cross section. We shall present its principle of operation along with the current and planned projects involving the Alpha-Gamma device, including the recalibration of the U.S. national neutron standard NBS-1 and (n,f) cross section measurements of 235U.
- Published
- 2019
25. Experimental Upper Bound and Theoretical Expectations for Parity-Violating Neutron Spin Rotation in 4He
- Author
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M. Sarsour, Jeffrey S. Nico, S. B. Walbridge, E. I. Sharapov, Hans P. Mumm, T. D. Bass, D. M. Markoff, J. C. Horton, H. E. Swanson, A. M. Micherdzinska, C.R. Huffer, D. Luo, C.D. Bass, Bret E. Crawford, J. M. Dawkins, V. Zhumabekova, K. Gan, W. M. Snow, and Blayne Heckel
- Subjects
Quantum chromodynamics ,Physics ,Particle physics ,010308 nuclear & particles physics ,Nuclear Theory ,FOS: Physical sciences ,Parity (physics) ,Weak interaction ,01 natural sciences ,Upper and lower bounds ,Article ,Amplitude ,0103 physical sciences ,Neutron ,High Energy Physics::Experiment ,Analysis tools ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nucleon ,Nuclear Experiment - Abstract
Neutron spin rotation is expected from quark-quark weak interactions in the Standard Model, which induce weak interactions among nucleons that violate parity. We present the results from an experiment searching for the effect of parity violation via the spin rotation of polarized neutrons in a liquid $^{4}$He medium. The value for the neutron spin rotation angle per unit length in $^{4}$He, $d\phi/dz =(+2.1 \pm 8.3 (stat.) \pm 2.9 (sys.))\times10^{-7}$ rad/m, is consistent with zero. The result agrees with the best current theoretical estimates of the size of nucleon-nucleon weak amplitudes from other experiments and with the expectations from recent theoretical approaches to weak nucleon-nucleon interactions. In this paper we review the theoretical status of parity violation in the $\vec{n}+^{4}$He system and discuss details of the data analysis leading to the quoted result. Analysis tools are presented that quantify systematic uncertainties in this measurement and that are expected to be essential for future measurements., Comment: 15 pages, 7 figures
- Published
- 2019
- Full Text
- View/download PDF
26. First Observation of P -odd γ Asymmetry in Polarized Neutron Capture on Hydrogen
- Author
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J. R. Calarco, C. Hayes, Dinko Pocanic, J. Hall, Charles Fieseler, V. Cianciolo, Xin Tong, S. Baeßler, S. Schröder, A. Ramírez-Morales, S. Santra, R. Whitehead, K. Craycraft, Kyle B. Grammer, E. Askanazi, P. N. Seo, S. Balascuta, Erik B. Iverson, A. Sprow, R. Mahurin, Ivan Novikov, J. Stewart, M. Musgrave, E. Frlež, N. Birge, Nadia Fomin, L. Alonzi, A. Salas-Bacci, I. Garishvili, W. M. Snow, Bernhard Lauss, S. Kucuker, W. S. Wilburn, M. Root, Timothy Chupp, D. Evans, Geoffrey Greene, Yasuhiro Masuda, Ricardo Alarcon, F. Simmons, H. Nann, M. Maldonado-Velázquez, M. L. Kabir, E. M. Scott, Robert Milburn, R. C. Gillis, J. D. Bowman, C. E. Coppola, M. McCrea, E. Tang, E. I. Sharapov, Michael Gericke, J. Fry, Christopher Crawford, S. I. Penttilä, D. Blyth, J. Hamblen, P. E. Mueller, Alexander Barzilov, L. Barrón-Palos, Z. Tang, J. Mei, D. Parsons, and D. J. Turkoglu
- Subjects
Coupling constant ,Physics ,Meson ,010308 nuclear & particles physics ,media_common.quotation_subject ,General Physics and Astronomy ,Spin isomers of hydrogen ,Coupling (probability) ,01 natural sciences ,Asymmetry ,Pion ,0103 physical sciences ,Effective field theory ,Neutron ,Atomic physics ,010306 general physics ,media_common - Abstract
We report the first observation of the parity-violating gamma-ray asymmetry A_{γ}^{np} in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at the Spallation Neutron Source at Oak Ridge National Laboratory. A_{γ}^{np} isolates the ΔI=1, ^{3}S_{1}→^{3}P_{1} component of the weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to a single coupling constant in either the DDH meson exchange model or pionless effective field theory. We measured A_{γ}^{np}=[-3.0±1.4(stat)±0.2(syst)]×10^{-8}, which implies a DDH weak πNN coupling of h_{π}^{1}=[2.6±1.2(stat)±0.2(syst)]×10^{-7} and a pionless EFT constant of C^{^{3}S_{1}→^{3}P_{1}}/C_{0}=[-7.4±3.5(stat)±0.5(syst)]×10^{-11} MeV^{-1}. We describe the experiment, data analysis, systematic uncertainties, and implications of the result.
- Published
- 2018
27. A Search for Possible Deviations from Newtonian Gravity at the nm Length Scale Using Neutron-Noble Gas Scattering
- Author
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Masaaki Kitaguchi, Hirohiko M. Shimizu, Kenji Mishima, Christopher C. Haddock, Tamaki Yoshioka, W. M. Snow, Tatsushi Shima, Takashi Ino, Katsuya Hirota, and Noriko Oi
- Subjects
Length scale ,Physics ,Gravity (chemistry) ,Scattering ,Newtonian fluid ,Neutron ,Noble gas (data page) ,Computational physics - Published
- 2018
28. A new approach to search for free neutron-antineutron oscillations using coherent neutron propagation in gas
- Author
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K.V. Protasov, Valery Nesvizhevsky, Vladimir Gudkov, W. M. Snow, A. Yu. Voronin, Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
- Subjects
Nuclear and High Energy Physics ,Nuclear Theory ,[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Neutron ,potential: optical ,Antineutron ,Computer Science::Digital Libraries ,01 natural sciences ,Nuclear Theory (nucl-th) ,Nuclear physics ,High Energy Physics - Phenomenology (hep-ph) ,gas ,propagation ,0103 physical sciences ,Nuclear Experiment ,010306 general physics ,n anti-n: oscillation ,Nuclear theory ,Physics ,density ,010308 nuclear & particles physics ,Oscillation ,baryon number ,Optical potential ,lcsh:QC1-999 ,coherence ,Magnetic field ,High Energy Physics - Phenomenology ,[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] ,Anti-neutron ,B-L number ,Baryon number ,magnetic field: external field ,lcsh:Physics ,Coherence (physics) - Abstract
Coherent forward neutron propagation in gas is discussed as a new approach to search for neutron-antineutron oscillations (n−n¯), which violate both B and B−L conservation. We show that one can increase the probability of neutron - antineutron transitions in the presence of a nonzero external magnetic field to essentially free neutron oscillation probability by tuning the density of an appropriate mixture of gases so that the neutron optical potential of the gas cancels that from the magnetic field.
- Published
- 2020
29. First Observation of P-odd γ Asymmetry in Polarized Neutron Capture on Hydrogen
- Author
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D, Blyth, J, Fry, N, Fomin, R, Alarcon, L, Alonzi, E, Askanazi, S, Baeßler, S, Balascuta, L, Barrón-Palos, A, Barzilov, J D, Bowman, N, Birge, J R, Calarco, T E, Chupp, V, Cianciolo, C E, Coppola, C B, Crawford, K, Craycraft, D, Evans, C, Fieseler, E, Frlež, I, Garishvili, M T W, Gericke, R C, Gillis, K B, Grammer, G L, Greene, J, Hall, J, Hamblen, C, Hayes, E B, Iverson, M L, Kabir, S, Kucuker, B, Lauss, R, Mahurin, M, McCrea, M, Maldonado-Velázquez, Y, Masuda, J, Mei, R, Milburn, P E, Mueller, M, Musgrave, H, Nann, I, Novikov, D, Parsons, S I, Penttilä, D, Počanić, A, Ramirez-Morales, M, Root, A, Salas-Bacci, S, Santra, S, Schröder, E, Scott, P-N, Seo, E I, Sharapov, F, Simmons, W M, Snow, A, Sprow, J, Stewart, E, Tang, Z, Tang, X, Tong, D J, Turkoglu, R, Whitehead, and W S, Wilburn
- Abstract
We report the first observation of the parity-violating gamma-ray asymmetry A_{γ}^{np} in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at the Spallation Neutron Source at Oak Ridge National Laboratory. A_{γ}^{np} isolates the ΔI=1, ^{3}S_{1}→^{3}P_{1} component of the weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to a single coupling constant in either the DDH meson exchange model or pionless effective field theory. We measured A_{γ}^{np}=[-3.0±1.4(stat)±0.2(syst)]×10^{-8}, which implies a DDH weak πNN coupling of h_{π}^{1}=[2.6±1.2(stat)±0.2(syst)]×10^{-7} and a pionless EFT constant of C^{^{3}S_{1}→^{3}P_{1}}/C_{0}=[-7.4±3.5(stat)±0.5(syst)]×10^{-11} MeV^{-1}. We describe the experiment, data analysis, systematic uncertainties, and implications of the result.
- Published
- 2018
30. A new cryogenic apparatus to search for the neutron electric dipole moment
- Author
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R. J. Holt, Seppo Penttila, S. Baessler, David G. Haase, C. R. Gould, M. E. Hayden, Dipangkar Dutta, S. W. T. MacDonald, L. Barrón-Palos, E. Korobkina, R. P. Redwine, Jen-Chieh Peng, Marcus H. Mendenhall, J. Long, Z. Tang, Haiyan Gao, Steven Clayton, Ross Milner, Evgeni Tsentalovich, J. Kelsey, Robert Golub, E. Ihloff, C. Vidal, S. E. Williamson, Matthew Busch, A. T. Holley, George M. Seidel, A. Saftah, M. Behzadipour, B. W. Filippone, M. Makela, Ayman I. Hawari, I. Berkutov, C. Osthelder, C. Daurer, Ricardo Alarcon, W. Yao, A. Reid, M. Broering, C. Swank, P. R. Huffman, S. Slutsky, Musa Ahmed, J. Leggett, Liang Yang, John Ramsey, Yu. Efremenko, H. O. Meyer, M. Blatnik, R. Carr, James Maxwell, T. D. S. Stanislaus, Scott Currie, E. S. Smith, W. M. Snow, A. Lipman, Takeyasu M. Ito, N. S. Phan, A. Aleksandrova, Leah Broussard, C.-Y. Liu, X. Sun, Steve K. Lamoreaux, K. A. Dow, Nima Nouri, D. P. Kendellen, A. Matlashov, R. Dipert, L. M. Bartoszek, K. K. H. Leung, C. O'Shaughnessy, M. Karcz, C. B. Erickson, Yongsun Kim, Wanchun Wei, A. R. Young, S. K. Imam, J. Bessuille, Geoffrey Greene, R. Tavakoli Dinani, T. M. Rao, S. Sosothikul, Douglas H Beck, D. Hasell, Wolfgang Korsch, P. E. Mueller, I.F. Silvera, C. R. White, M. D. Cooper, Christopher Crawford, Nadia Fomin, W. E. Sondheim, Brad Plaster, and V. Cianciolo
- Subjects
Physics ,Physics - Instrumentation and Detectors ,Neutron electric dipole moment ,010308 nuclear & particles physics ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,Oak Ridge National Laboratory ,01 natural sciences ,030218 nuclear medicine & medical imaging ,Superfluidity ,Nuclear physics ,03 medical and health sciences ,0302 clinical medicine ,Electric field ,0103 physical sciences ,Limit (music) ,Neutron ,Sensitivity (control systems) ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,Instrumentation ,Mathematical Physics ,Spallation Neutron Source - Abstract
© 2019 IOP Publishing Ltd and Sissa Medialab. A cryogenic apparatus is described that enables a new experiment, nEDM@SNS, with a major improvement in sensitivity compared to the existing limit in the search for a neutron Electric Dipole Moment (EDM). This apparatus uses superfluid 4He to produce a high density of Ultra-Cold Neutrons (UCN) which are contained in a suitably coated pair of measurement cells. The experiment, to be operated at the Spallation Neutron Source at Oak Ridge National Laboratory, uses polarized 3He from an Atomic Beam Source injected into the superfluid 4He and transported to the measurement cells where it serves as a co-magnetometer. The superfluid 4He is also used as an insulating medium allowing significantly higher electric fields, compared to previous experiments, to be maintained across the measurement cells. These features provide an ultimate statistical uncertainty for the EDM of 2-3× 10-28 e-cm, with anticipated systematic uncertainties below this level.
- Published
- 2019
31. Measurement of the absolute neutron beam polarization from a supermirror polarizer and the absolute efficiency of a neutron spin rotator for the NPDGamma experiment using a polarized $^{3}$He neutron spin-filter
- Author
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S. Balascuta, P. R. Huffman, P. E. Mueller, M.M. Musgrave, D. Blyth, W. M. Snow, V. Cianciolo, Nadia Fomin, Geoffrey Greene, J. D. Bowman, Christopher Crawford, C. Hayes, M. McCrea, E. Tang, J. Hamblen, L. Barrón-Palos, K. Craycraft, Zhaowen Tang, Kyle B. Grammer, S. Kucuker, W. S. Wilburn, Chenyang Jiang, Xin Tong, S. Baeßler, R. C. Gillis, Seppo Penttila, Timothy Chupp, Michael Gericke, and J. Fry
- Subjects
Nuclear and High Energy Physics ,Physics - Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,FOS: Physical sciences ,01 natural sciences ,law.invention ,Nuclear physics ,law ,0103 physical sciences ,Neutron ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Instrumentation ,Physics ,010308 nuclear & particles physics ,Instrumentation and Detectors (physics.ins-det) ,Polarizer ,Neutron radiation ,3. Good health ,Neutron capture ,Beamline ,Neutron source ,Physics::Accelerator Physics ,Spallation Neutron Source ,Beam (structure) - Abstract
Accurately measuring the neutron beam polarization of a high flux, large area neutron beam is necessary for many neutron physics experiments. The Fundamental Neutron Physics Beamline (FnPB) at the Spallation Neutron Source (SNS) is a pulsed neutron beam that was polarized with a supermirror polarizer for the NPDGamma experiment. The polarized neutron beam had a flux of $\sim10^9$ neutrons per second per cm$^2$ and a cross sectional area of 10$\times$12~cm$^2$. The polarization of this neutron beam and the efficiency of a RF neutron spin rotator installed downstream on this beam were measured by neutron transmission through a polarized $^{3}$He neutron spin-filter. The pulsed nature of the SNS enabled us to employ an absolute measurement technique for both quantities which does not depend on accurate knowledge of the phase space of the neutron beam or the $^{3}$He polarization in the spin filter and is therefore of interest for any experiments on slow neutron beams from pulsed neutron sources which require knowledge of the absolute value of the neutron polarization. The polarization and spin-reversal efficiency measured in this work were done for the NPDGamma experiment, which measures the parity violating $\gamma$-ray angular distribution asymmetry with respect to the neutron spin direction in the capture of polarized neutrons on protons. The experimental technique, results, systematic effects, and applications to neutron capture targets are discussed., Comment: 13 pages, 14 figures, 2 tables
- Published
- 2018
32. A Search for Possible Long Range Spin Dependent Interactions of the Neutron From Exotic Vector Boson Exchange
- Author
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E. Anderson, W. Fox, H. E. Swanson, K. Steffen, K. Korsak, Takuya Okudaira, L. Barrón-Palos, Christopher C. Haddock, I. Francis, J. Lieffers, P. A. Yergeau, M. Maldonado-Velázquez, A. T. Holley, Aaron Sprow, Bret E. Crawford, W. M. Snow, H. Gardiner, S. Magers, Fredrik Tovesson, Swadeshmukul Santra, Christopher Crawford, Hirohiko M. Shimizu, J. Amadio, J. Fry, D. Esposito, J. Vanderwerp, D.A. Mayorov, Jeffrey S. Nico, M. Sarsour, and C. Paudel
- Subjects
Coupling ,Physics ,Nuclear and High Energy Physics ,Physics - Instrumentation and Detectors ,010308 nuclear & particles physics ,FOS: Physical sciences ,Polarimeter ,Instrumentation and Detectors (physics.ins-det) ,Polarization (waves) ,01 natural sciences ,3. Good health ,Vector boson ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,0103 physical sciences ,Neutron ,Slow neutron ,Atomic physics ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Pseudovector ,Boson - Abstract
We present a search for possible spin dependent interactions of the neutron with matter through exchange of spin 1 bosons with axial vector couplings as envisioned in possible extensions of the Standard Model. This was sought using a slow neutron polarimeter that passed transversely polarized slow neutrons by unpolarized slabs of material arranged so that this interaction would tilt the plane of polarization and develop a component along the neutron momentum. The result for the rotation angle, $\phi'_{V_5} = [2.8\pm\,4.6(stat.)\pm\,4.0(sys.)]\times 10^{-5}~\mbox{rad/m}$ is consistent with zero. This result improves the upper bounds on the neutron-matter coupling $g_{A}^{2}$ from such an interaction by about three orders of magnitude for force ranges in the mm-$\mu$m regime., Comment: 10 pages, 3 figures
- Published
- 2018
- Full Text
- View/download PDF
33. Calculations of Neutron Reflectivity in the eV Energy Range from Mirrors made of Heavy Nuclei with Neutron-Nucleus Resonances
- Author
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K. A. Dickerson, Christopher C. Haddock, J. S. Devaney, and W. M. Snow
- Subjects
Physics - Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,FOS: Physical sciences ,7. Clean energy ,01 natural sciences ,010305 fluids & plasmas ,symbols.namesake ,0103 physical sciences ,Dispersion (optics) ,Surface roughness ,Neutron ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Physics ,Range (particle radiation) ,Phonon scattering ,Scattering ,Instrumentation and Detectors (physics.ins-det) ,3. Good health ,symbols ,Atomic physics ,Doppler effect ,Doppler broadening - Abstract
We evaluate the reflectivity of neutron mirrors composed of certain heavy nuclei which possess strong neutron-nucleus resonances in the eV energy range. We show that the reflectivity of such a mirror for some nuclei can in principle be high enough near energies corresponding to compound neutron-nucleus resonances to be of interest for certain scientific applications in non-destructive evaluation of subsurface material composition and in the theory of neutron optics beyond the kinematic limit., Comment: 18 pages, 5 figures, 1 table
- Published
- 2018
- Full Text
- View/download PDF
34. Progress on the ARIADNE Axion Experiment
- Author
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E. Wiesman, Asimina Arvanitaki, M. Harkness, W. M. Snow, Yannis K. Semertzidis, J. Shortino, Y. Shin, Chen-Yu Liu, H. Fosbinder-Elkins, Edward Smith, Aharon Kapitulnik, Mark Cunningham, Samuel Mumford, Y. H. Lee, I. Lee, Janet C. Long, J. Dargert, Chloe Lohmeyer, and Eli Levenson-Falk
- Subjects
Quantum chromodynamics ,Physics ,Superconductivity ,Particle physics ,Physics::Instrumentation and Detectors ,010308 nuclear & particles physics ,Magnetometer ,High Energy Physics::Phenomenology ,Fifth force ,Fermion ,01 natural sciences ,Magnetic field ,law.invention ,law ,0103 physical sciences ,Electromagnetic shielding ,010306 general physics ,Axion - Abstract
The Axion Resonant InterAction Detection Experiment (ARIADNE) is a collaborative effort to search for the QCD axion using techniques based on nuclear magnetic resonance (Arvanitaki and Geraci, Phys Rev Lett 113:161801, 2014). In the experiment, axions or axion-like particles would mediate short-range spin-dependent interactions between a laser-polarized3He gas and a rotating (unpolarized) tungsten source mass, acting as a tiny, fictitious magnetic field. The experiment has the potential to probe deep within the theoretically interesting regime for the QCD axion in the mass range of 0.1–10 meV, independently of cosmological assumptions. The experiment relies on a stable rotary mechanism and superconducting magnetic shielding, required to screen the 3He sample from ordinary magnetic noise. Progress on testing the stability of the rotary mechanism is reported, and the design for the superconducting shielding is discussed.
- Published
- 2018
35. Fundamental physics activities with pulsed neutron at J-PARC(BL05)
- Author
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Christopher C. Haddock, T. Tomita, Naotaka Naganawa, T. Shima, S. Imajo, Tamaki Yoshioka, Hirohiko M. Shimizu, Hidetoshi Otono, S. Awano, M. Yokohashi, M. Hirose, Naoyuki Sumi, Masahiro Hino, Takahito Yamada, Yasuhiro Fuwa, Jun Koga, Noriko Oi, Satoru Yamashita, S. Tasaki, Yoshichika Seki, Naoki Nagakura, A. Umemoto, S. Ieki, Kaoru Taketani, Hirochika Sumino, Katsuya Hirota, Kenji Mishima, Takashi Ino, S. Tada, Hiroaki Kawahara, Ryo Katayama, Daiichiro Sekiba, Fumiya Goto, Y. Iwashita, Masaaki Kitaguchi, Ryunosuke Kitahara, A. Morishita, W. M. Snow, Tomofumi Nagae, and Hideyuki Oide
- Subjects
Physics ,Physics - Instrumentation and Detectors ,Physics::Instrumentation and Detectors ,Detector ,FOS: Physical sciences ,Elementary particle ,Instrumentation and Detectors (physics.ins-det) ,Neutron scattering ,High Energy Physics - Experiment ,Nuclear physics ,High Energy Physics - Experiment (hep-ex) ,Beamline ,Neutron detection ,Neutron ,J-PARC ,Nuclear Experiment ,Beam (structure) - Abstract
"Neutron Optics and Physics (NOP/ BL05)" at MLF in J-PARC is a beamline for studies of fundamental physics. The beamline is divided into three branches so that different experiments can be performed in parallel. These beam branches are being used to develop a variety of new projects. We are developing an experimental project to measure the neutron lifetime with total uncertainty of 1 s (0.1%). The neutron lifetime is an important parameter in elementary particle and astrophysics. Thus far, the neutron lifetime has been measured by several groups; however, different values are obtained from different measurement methods. This experiment is using a method with different sources of systematic uncertainty than measurements conducted to date. We are also developing a source of pulsed ultra-cold neutrons (UCNs) produced from a Doppler shifter are available at the unpolarized beam branch. We are developing a time focusing device for UCNs, a so called "rebuncher", which can increase UCN density from a pulsed UCN source. At the low divergence beam branch, an experiment to search an unknown intermediate force with nanometer range is performed by measuring the angular dependence of neutron scattering by noble gases. Finally the beamline is also used for the research and development of optical elements and detectors. For example, a position sensitive neutron detector that uses emulsion to achieve sub-micrometer resolution is currently under development. We have succeeded in detecting cold and ultra-cold neutrons using the emulsion detector., 9 pages, 5 figures, Proceedings of International Conference on Neutron Optics (NOP2017)
- Published
- 2017
36. Fundamental neutron physics beamline at the spallation neutron source at ORNL
- Author
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P. R. Huffman, Erik B. Iverson, T.M. Tito, R.R. Allen, V. Cianciolo, Christopher Crawford, W. M. Snow, R. Mahurin, Nadia Fomin, and Geoffrey Greene
- Subjects
Accelerator Physics (physics.acc-ph) ,Physics ,Nuclear and High Energy Physics ,Physics - Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,FOS: Physical sciences ,Instrumentation and Detectors (physics.ins-det) ,Oak Ridge National Laboratory ,Neutron scattering ,Cosmology ,3. Good health ,Nuclear physics ,Beamline ,Physics::Accelerator Physics ,Neutron detection ,Physics - Accelerator Physics ,Spallation ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,Instrumentation ,Spallation Neutron Source ,Beam (structure) - Abstract
We describe the Fundamental Neutron Physics Beamline (FnPB) facility located at the Spallation Neutron Source at Oak Ridge National Laboratory. The FnPB was designed for the conduct of experiments that investigate scientific issues in nuclear physics, particle physics, astrophysics and cosmology using a pulsed slow neutron beam. We present a detailed description of the design philosophy, beamline components, and measured fluxes of the polychromatic and monochromatic beams.
- Published
- 2015
37. Constraining Spacetime Nonmetricity with Neutron Spin Rotation in Liquid He-4
- Author
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Zhi Xiao, Ralf Lehnert, Rui Xu, and W. M. Snow
- Subjects
Nuclear and High Energy Physics ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Context (language use) ,Rotation ,01 natural sciences ,Quantitative Biology::Cell Behavior ,Theoretical physics ,General Relativity and Quantum Cosmology ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,Effective field theory ,ddc:530 ,Neutron ,Nuclear Experiment ,010306 general physics ,Spin-½ ,Physics ,Spacetime ,010308 nuclear & particles physics ,Space time ,Isotropy ,Quantitative Biology::Genomics ,lcsh:QC1-999 ,High Energy Physics - Phenomenology ,Classical mechanics ,Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik ,lcsh:Physics - Abstract
General spacetime nonmetricity coupled to neutrons is studied. In this context, it is shown that certain nonmetricity components can generate a rotation of the neutron's spin. Available data on this effect obtained from slow-neutron propagation in liquid helium are used to constrain isotropic nonmetricity components at the level of $10^{-22}\,$GeV. These results represent the first limit on the nonmetricity $\zeta^{(6)}_2S_{000}$ parameter as well as the first measurement of nonmetricity inside matter., Comment: 5 pages, accepted for publication in Physics Letters B
- Published
- 2017
38. Observation of coherent elastic neutrino-nucleus scattering
- Author
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S. Ki, M. Hai, C. Leadbetter, G. Perumpilly, Seppo Penttila, Belkis Cabrera-Palmer, N. Fields, Alexander Bolozdynya, W. Fox, Erik B. Iverson, C.-H. Yu, Bjorn Scholz, R. L. Varner, J. Raybern, S. R. Elliott, S. R. Klein, M. P. Green, J. A. Detwiler, Jason Newby, Yuri Efremenko, C. J. Virtue, G.C. Rich, John L. Orrell, Lorenzo Fabris, Jaeun Yoo, L. J. Kaufman, D. M. Markoff, Kathryn Mann, B. Becker, Michael Febbraro, A. V. Kumpan, B. Suh, A. Eberhardt, P. E. Mueller, Robert Cooper, D. Rudik, Z. Fu, H. Moreno, P. An, J. Vanderwerp, David Reyna, C. Cuesta, Z. Wan, R. Tayloe, A. Konovalov, Liang Li, Kate Scholberg, G. Sinev, Todd W. Hossbach, A. Shakirov, A.V. Khromov, A. Zawada, April S. Brown, D. Hornback, J. Zettlemoyer, S. Hedges, V.V. Sosnovtsev, Reynold J. Cooper, Justin Albert, A. Galindo-Uribarri, M. Cervantes, I. Tolstukhin, J. I. Collar, W. M. Snow, D. Akimov, D. J. Dean, Rod Thornton, S. Suchyta, Diana Parno, A. M. Zderic, E. M. Erkela, Cory T. Overman, W. Lu, D. Rimal, K. Miller, M. Kremer, C. Awe, M.R. Heath, P. S. Barbeau, V. A. Belov, and H. Ray
- Subjects
Quark ,Nuclear Theory ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Scintillator ,01 natural sciences ,Standard Model ,High Energy Physics - Experiment ,Nuclear physics ,Nuclear Theory (nucl-th) ,High Energy Physics - Experiment (hep-ex) ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Elastic scattering ,Physics ,Multidisciplinary ,010308 nuclear & particles physics ,Scattering ,Detector ,High Energy Physics - Phenomenology ,High Energy Physics::Experiment ,Neutrino ,Spallation Neutron Source - Abstract
Detecting neutrinos—elementary particles that barely interact with other matter—usually requires detectors of enormous size. A particular interaction of neutrinos with atomic nuclei, called the coherent elastic neutrino-nucleus scattering (CEνNS), is predicted to occur with relatively high probability, and it could be used to drastically reduce the size of neutrino detectors. However, observing this interaction requires a source of low-energy neutrinos and detectors that contain nuclei of optimal mass. Akimov et al. observed CEνNS with a 6.7σ confidence by using a comparatively tiny, 14.6-kg sodium-doped CsI scintillator exposed to neutrinos from a spallation neutron facility (see the Perspective by Link). The discovery places tighter bounds on exotic, beyond-the-standard-model interactions involving neutrinos. Science , this issue p. [1123][1]; see also p. [1098][2] [1]: /lookup/doi/10.1126/science.aao0990 [2]: /lookup/doi/10.1126/science.aao4050
- Published
- 2017
39. Searching for Exotic Monopole-Dipole Interactions between Nucleons Using NMR Measurements with an Optically-Pumped Polarized Xenon Comagnetometer
- Author
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T. Wager, J. Shortino, E. S. Smith, Anna Korver, Thad Walker, A. Din, Daniel Thrasher, W. M. Snow, H. Singh, J. Bohorquez, and Michael Peters
- Subjects
Physics ,Dipole ,Xenon ,chemistry ,Magnetic monopole ,chemistry.chemical_element ,Atomic physics ,Nucleon - Published
- 2017
40. Facilities for Fundamental Neutron Physics Research at the NIST Cold Neutron Research Facility
- Author
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G. L. Greene, Muhammad Arif, W. M. Snow, and Maynard S. Dewey
- Subjects
Physics ,ComputerSystemsOrganization_COMPUTERSYSTEMIMPLEMENTATION ,neutron lifetime ,Nuclear engineering ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,General Engineering ,Hardware_PERFORMANCEANDRELIABILITY ,neutron interferometry ,Article ,vibration isolation ,Neutron physics ,neutron decay ,Nuclear physics ,Neutron research facility ,ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION ,Measuring instrument ,Computer Science::Networking and Internet Architecture ,NIST ,Neutron detection ,Neutron ,neutron wave ,Physics::Atomic Physics ,beta decay ,Nuclear Experiment - Abstract
The features of two fundamental neutron physics research stations at the NIST cold neutron research facility are described in some detail. A list of proposed initial experimental programs for these two stations is also given.
- Published
- 2017
41. Decoupling of a neutron interferometer from temperature gradients
- Author
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Chandra Shahi, Ke Li, Taisiya Mineeva, W. M. Snow, Dmitry A. Pushin, V. Skavysh, Michael G. Huber, P. Saggu, Robert Haun, Ben Heacock, J. Nsofini, Dusan Sarenac, Muhammad Arif, David G. Cory, Samuel A. Werner, and Albert Young
- Subjects
Materials science ,Physics - Instrumentation and Detectors ,010308 nuclear & particles physics ,business.industry ,FOS: Physical sciences ,Decoupling (cosmology) ,Acoustic wave ,Instrumentation and Detectors (physics.ins-det) ,01 natural sciences ,Article ,Interferometry ,Optics ,Perfect crystal ,0103 physical sciences ,Electromagnetic shielding ,Neutron ,Vacuum chamber ,010306 general physics ,business ,Instrumentation ,Neutron interferometer - Abstract
Neutron interferometry enables precision measurements that are typically operated within elaborate, multi-layered facilities which provide substantial shielding from environmental noise. These facilities are necessary to maintain the coherence requirements in a perfect crystal neutron interferometer which is extremely sensitive to local environmental conditions such as temperature gradients across the interferometer, external vibrations, and acoustic waves. The ease of operation and breadth of applications of perfect crystal neutron interferometry would greatly benefit from a mode of operation which relaxes these stringent isolation requirements. Here, the INDEX Collaboration and National Institute of Standards and Technology demonstrates the functionality of a neutron interferometer in vacuum and characterize the use of a compact vacuum chamber enclosure as a means to isolate the interferometer from spatial temperature gradients and time-dependent temperature fluctuations. The vacuum chamber is found to have no depreciable effect on the performance of the interferometer (contrast) while improving system stability, thereby showing that it is feasible to replace large temperature isolation and control systems with a compact vacuum enclosure for perfect crystal neutron interferometry.
- Published
- 2017
42. A Frequency Determination Method for Digitized NMR Signals
- Author
-
Haiyan Gao, W. Zheng, C. B. Fu, K. Li, Elton Smith, H. Yan, R. Khatiwada, Pinghan Chu, and W. M. Snow
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,020209 energy ,Acoustics ,Noise reduction ,020208 electrical & electronic engineering ,FOS: Physical sciences ,Probability and statistics ,02 engineering and technology ,Computational Physics (physics.comp-ph) ,Frequency determination ,Numerical integration ,Physics - Data Analysis, Statistics and Probability ,0202 electrical engineering, electronic engineering, information engineering ,Physics - Computational Physics ,Data Analysis, Statistics and Probability (physics.data-an) - Abstract
We present a high precision frequency determination method for digitized NMR FID signals. The method employs high precision numerical integration rather than simple summation as in many other techniques. With no independent knowledge of the other parameters of a NMR FID signal (phase ф, amplitude A, and transverse relaxation time T2) this method can determine the signal frequency f0 with a precision of if the observation time T ≫ T2. The method is especially convenient when the detailed shape of the observed FT NMR spectrum is not well defined. When T2 is +∞ and the signal becomes pure sinusoidal, the precision of the method is which is one order more precise than the ±1 count error induced precision of a typical frequency counter. Analysis of this method shows that the integration reduces the noise by bandwidth narrowing as in a lock-in amplifier, and no extra signal filters are needed. For a pure sinusoidal signal we find from numerical simulations that the noise-induced error in this method reaches the Cramer-Rao Lower Band (CRLB) on frequency determination. For the damped sinusoidal case of most interest, the noise-induced error is found to be within a factor of 2 of CRLB when the measurement time T is 2 or 3 times larger than T2. We discuss possible improvements for the precision of this method.
- Published
- 2014
43. LENS: 2013 Facility Overview
- Author
-
W. M. Snow, S. R. Parnell, Roger Pynn, S. Aldaihan, T. Rinckel, David V. Baxter, and Paul Sokol
- Subjects
Physics ,010308 nuclear & particles physics ,Nuclear engineering ,accelerator-driven neutron source ,02 engineering and technology ,Neutron radiation ,Physics and Astronomy(all) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Neutron moderator ,neutron pulse shapes ,law.invention ,Nuclear physics ,Lens (optics) ,Low energy ,law ,0103 physical sciences ,Neutron source ,Neutron ,0210 nano-technology - Abstract
The Low Energy Neutron Source at Indiana University began construction in the fall of 2003, and the facility has now been producing cold neutrons for approximately 8 years. LENS now has three instruments in operation on its cold target station as well as a facility for investigating neutron radiation effects on a second target station. Instrumentation development continues to represent a significant fraction of the activity at LENS, with the current activities focused primarily on neutron spin manipulation and moderator development. Research into the effects of confinement on simple and complex fluids has dominated our materials investigations. In this paper, we summarize recent activities in these areas using each of the instruments and provide an update on our operational experience over the last few years.
- Published
- 2014
- Full Text
- View/download PDF
44. Fundamental Neutron Physics with Long Pulsed Spallation Sources
- Author
-
W. M. Snow
- Subjects
Physics ,Neutron physics ,weak nucleon-nucleon interaction ,Astrophysics::High Energy Astrophysical Phenomena ,Nuclear Theory ,Neutron scattering ,Physics and Astronomy(all) ,Neutron time-of-flight scattering ,Neutron temperature ,neutron decay ,time reversal violation ,spallation ,Nuclear physics ,Neutron cross section ,Neutron source ,Neutron detection ,Neutron ,Nuclear Experiment ,dark energy ,Spallation Neutron Source - Abstract
We discuss the advantages that a long-pulse spallation neutron source like the ESS can provide for certain types of slow neutron experiments in the general area of nuclear/particle/astrophysics. A long-pulse spallation neutron source can provide the best balance between the need for increased neutron intensity combined with enough information on the slow neutron energy spectrum at the experiment with the neutron source off to maximize the signal/background ratio and help diagnose systematic errors for many different types of experiments in this field. We discuss a few examples of different types of slow neutron experiments which we feel can take best advantage of a long-pulse mode of operation.
- Published
- 2014
- Full Text
- View/download PDF
45. Status of the NPDGamma experiment
- Author
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C. Garcia, E. Frlež, E. Askanazi, S. Balascuta, Dinko Pocanic, D. Evans, P. N. Seo, H. Nann, Kyle B. Grammer, M. Musgrave, Gregory S. Mitchell, Bernhard Lauss, R. Mahurin, D. Blyth, F. Simmons, Geoffrey Greene, V.W. Yuan, E. Tang, L. Kabir, S. A. Page, J. R. Calarco, Ricardo Alarcon, C. Hayes, Timothy Chupp, Yi-De Zhang, T. Tong, Erik B. Iverson, C. E. Coppola, L. Barrón-Palos, Alexander Barzilov, W. Fox, Charles Fieseler, I. Garishvili, K. Craycraft, J. Stuart, F. W. Hersman, Y. Li, Z. Tang, M. Sharma, R. Allen, Christopher Crawford, J. Vanderwerp, Gordon L. Jones, P. E. Mueller, J. Hamblen, Yasuhiro Masuda, S. I. Penttilä, Robert Milburn, S. Baeßler, A. Salas-Bacci, C. Fu, D. Parsons, Ivan Novikov, E. I. Sharapov, Takashi Ino, Nadia Fomin, S. Kucucker, Stuart J. Freedman, J. Thomison, W. D. Ramsay, Michael Gericke, C. Blessinger, M. Maldonado-Velázquez, J. Fry, M. Dabaghyan, R. C. Gillis, M. McCrea, S. Waldecker, J. Mei, T. B. Smith, J. D. Bowman, S. Santra, Suguru Muto, W. M. Snow, W. Xu, W. S. Wilburn, and J. Favela
- Subjects
Nuclear and High Energy Physics ,Particle physics ,Meson ,media_common.quotation_subject ,Nuclear Theory ,Hadron ,Weak interaction ,01 natural sciences ,7. Clean energy ,Asymmetry ,Nuclear physics ,0103 physical sciences ,Neutron ,Physical and Theoretical Chemistry ,Nuclear Experiment ,010306 general physics ,media_common ,Physics ,010308 nuclear & particles physics ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Neutron capture ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,Nucleon ,Spallation Neutron Source - Abstract
The NPDGamma experiment measures the parity-violating (PV) gamma asymmetry from polarized cold neutrons captured on protons at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The (PV) neutron spin asymmetry A γ of photons from polarized cold neutron capture on protons is proportional to the ΔI=1 long range weak meson coupling $h_{\pi }^{1}$ between nucleons in the hadronic weak interaction (HWI). Liquid para-hydrogen production data taking concluded in April 2014 and once the background aluminum asymmetry measurements are complete, the PV asymmetry A γ can be extracted. Preliminary results of the analysis of A γ are presented.
- Published
- 2016
46. Parity-even and time-reversal-odd neutron optical potential in spinning matter induced by gravitational torsion
- Author
-
A. N. Ivanov and W. M. Snow
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010308 nuclear & particles physics ,Torsion (mechanics) ,FOS: Physical sciences ,Parity (physics) ,General Relativity and Quantum Cosmology (gr-qc) ,01 natural sciences ,Optical potential ,Helicity ,General Relativity and Quantum Cosmology ,lcsh:QC1-999 ,Gravitation ,Pseudoscalar ,0103 physical sciences ,Neutron ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Spinning ,lcsh:Physics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Recent theoretical work has shown that spin $1/2$ particles moving through unpolarized matter which sources torsion fields experience a new type of parity-even and time-reversal-odd optical potential if the matter is spinning in the lab frame. This new type of optical potential can be sought experimentally using the helicity dependence of the total cross sections for longitudinally polarized neutrons moving through a rotating cylindrical target. In combination with recent experimental constraints on short-range P--odd, T--even torsion interactions derived from polarized neutron spin rotation in matter one can derive separate constraints on the time components of scalar and pseudoscalar torsion fields in matter. We estimate the sensitivity achievable in such an experiment and briefly outline some of the potential sources of systematic error to be considered in any future experimental search for this effect., Comment: 5 pages, no figures, to appear in Physics Letters B
- Published
- 2016
47. Calculations of the dominant long-range, spin-independent contributions to the interaction energy between two nonrelativistic Dirac fermions from double-boson exchange of spin-0 and spin-1 bosons with spin-dependent couplings
- Author
-
W. M. Snow, Dennis E. Krause, S. Aldaihan, and Josh Long
- Subjects
Physics ,Particle physics ,010308 nuclear & particles physics ,Physics beyond the Standard Model ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,Fermion ,01 natural sciences ,General Relativity and Quantum Cosmology ,3. Good health ,High Energy Physics - Experiment ,Pseudoscalar ,High Energy Physics - Experiment (hep-ex) ,symbols.namesake ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Dirac fermion ,0103 physical sciences ,symbols ,010306 general physics ,Nucleon ,Pseudovector ,Spin-½ ,Boson - Abstract
Various theories beyond the Standard Model predict new particles with masses in the sub-eV range with very weak couplings to ordinary matter which can possess spin-dependent couplings to electrons and nucleons. Present laboratory constraints on exotic spin-dependent interactions with pseudoscalar and axial couplings for exchange boson masses between meV and eV are very poor compared to constraints on spin-independent interactions in the same mass range arising from spin-0 and spin-1 boson exchange. It is therefore interesting to analyze in a general way how one can use the strong experimental bounds on spin-independent interactions to also constrain spin-dependent interactions by considering higher-order exchange processes. The exchange of a pair of bosons between two fermions with spin-dependent couplings will possess contributions which flip spins twice and thereby generate a polarization-independent interaction energy which can add coherently between two unpolarized objects. In this paper we derive the dominant long-range contributions to the interaction energy between two nonrelativistic spin-1/2 Dirac fermions from double exchange of spin-0 and spin-1 bosons proportional to couplings of the form $g_P^{4}$, $g_S^{2}g_P^{2}$, and $g_V^{2}g_A^{2}$. Our results for $g_P^{4}$ are in agreement with previous calculations that have appeared in the literature. We demonstrate the usefulness of this analysis to constrain spin-dependent couplings by presenting the results of a reanalysis of data from a short-range gravity experiment to derive an improved constraint on $(g^N_{P})^2$, the pseudoscalar coupling for nucleons, in the range between $40$ and $200~\mu$m of about a factor of 5 compared to previous limits. The spin-independent contribution from 2-boson exchange with axial-vector couplings requires special treatment and will be explored in another paper., Comment: 9 pages, 2 figures
- Published
- 2016
48. Neutron spin rotation measurements
- Author
-
Shannon Fogwell Hoogerheide, C. Paudel, L. Barrón-Palos, W. M. Snow, J. Fry, K. Korsak, K. Steen, Takuya Okudaira, Christopher Crawford, W. Fox, A. Holly, H. E. Gardiner, Hans P. Mumm, D.A. Mayorov, M. Sarsour, I. Francis, D. Esposito, Aaron Sprow, J. Vanderwerp, Christopher C. Haddock, Bret E. Crawford, Hirohiko M. Shimizu, J. Amadio, Fredrik Tovesson, J. Lieers, P. A. Yergeau, Jeffrey S. Nico, S. Magers, E. Anderson, H. E. Swanson, M. Maldonado-Velázquez, and Swadeshmukul Santra
- Subjects
Quantum chromodynamics ,Physics ,Nuclear physics ,Coupling constant ,Beamline ,QC1-999 ,Neutron ,Polarimeter ,Weak measurement ,Polarization (waves) ,Nucleon - Abstract
The neutron spin rotation (NSR) collaboration used parity-violating spin rotation of transversely polarized neutrons transmitted through a 0.5 m liquid helium target to constrain weak coupling constants between nucleons. While consistent with theoretical expectation, the upper limit set by this measurement on the rotation angle is limited by statistical uncertainties. The NSR collaboration is preparing a new measurement to improve this statistically-limited result by about an order of magnitude. In addition to using the new high-flux NG-C beam at the NIST Center for Neutron Research, the apparatus was upgraded to take advantage of the larger-area and more divergent NG-C beam. Significant improvements are also being made to the cryogenic design. Details of these improvements and readiness of the upgraded apparatus are presented. We also comment on how recent theoretical work combining effective field theory techniques with the 1/Nc expansion of QCD along with previous NN weak measurements can be used to make a prediction for dϕ/dz in 4He. An experiment using the same apparatus with a room-temperature target was carried out at LANSCE to place limits on parity-conserving rotations from possible fifth-force interactions to complement previous studies. We sought this interaction using a slow neutron polarimeter that passed transversely polarized slow neutrons by unpolarized slabs of material arranged so that this interaction would tilt the plane of polarization and develop a component along the neutron momentum. The results of this measurement and its impact on the neutron-matter coupling gA2 from such an interaction are presented. The NSR collaboration is also preparing a new measurement that uses an upgraded version of the room-temperature target to be run on the NG-C beamline; and it is expected to constrain gA2 by at least two additional orders of magnitude for λc between 1 cm and 1 μm.
- Published
- 2019
49. The neutron electric dipole moment experiment at the Spallation Neutron Source
- Author
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Scott Currie, John Ramsey, Haiyan Gao, Dipangkar Dutta, Jen-Chieh Peng, Y.J. Kim, A. Lipman, A. Matlashov, E. Ihloff, M. Blatnik, E. Korobkina, M. McCrea, P. R. Huffman, C. R. Gould, C. M. O'Shaughnessy, Brad Plaster, D. Hasell, T. Rao, Mark Makela, T. D. S. Stanislaus, Wanchun Wei, C. B. Erickson, S. Baeßler, Nima Nouri, M. E. Hayden, Liang Yang, M. Broering, Ayman I. Hawari, S. Sosothikul, Yu. Efremenko, S. E. Williamson, P. E. Mueller, L. M. Bartoszek, K. K. H. Leung, A. R. Young, L. Barrón-Palos, Seppo Penttila, J. Bessuille, Geoffrey Greene, Steve K. Lamoreaux, K. A. Dow, S. W. T. MacDonald, Leah Broussard, Douglas H Beck, M. Behzadipour, Ricardo Alarcon, W. Yao, S. Slutsky, Christopher Crawford, A. Aleksandrova, R. Tavakoli Dinani, David G. Haase, Evgeni Tsentalovich, R. J. Holt, Z. Tang, R. P. Redwine, J. Kelsey, Matthew Busch, E. Leggett, A. Saftah, Steven Clayton, Ross Milner, M. W. Ahmed, Nadia Fomin, C. Vidal, Wolfgang Korsch, V. Cianciolo, E. Smith, I.F. Silvera, C. R. White, Marcus H. Mendenhall, J. Long, R. Dipert, Robert Golub, A. T. Holley, C. Osthelder, R. Carr, W. M. Snow, George M. Seidel, B. W. Filippone, W. E. Sondheim, Takeyasu M. Ito, N. S. Phan, C. Daurer, M. D. Cooper, A. Reid, C. Swank, James Maxwell, X. Sun, Pinghan Chu, H. O. Meyer, and C.-Y. Liu
- Subjects
Physics ,Physics - Instrumentation and Detectors ,Neutron electric dipole moment ,010308 nuclear & particles physics ,QC1-999 ,FOS: Physical sciences ,Field strength ,Instrumentation and Detectors (physics.ins-det) ,7. Clean energy ,01 natural sciences ,Nuclear physics ,Electric field ,0103 physical sciences ,Electromagnetic shielding ,Precession ,Ultracold neutrons ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Spin (physics) ,Nuclear Experiment ,Spallation Neutron Source - Abstract
Novel experimental techniques are required to make the next big leap in neutron electric dipole moment experimental sensitivity, both in terms of statistics and systematic error control. The nEDM experiment at the Spallation Neutron Source (nEDM@SNS) will implement the scheme of Golub & Lamoreaux [Phys. Rep., 237, 1 (1994)]. The unique properties of combining polarized ultracold neutrons, polarized $^3$He, and superfluid $^4$He will be exploited to provide a sensitivity to $\sim 10^{-28}\,e{\rm \,\cdot\, cm}$. Our cryogenic apparatus will deploy two small ($3\,{\rm L}$) measurement cells with a high density of ultracold neutrons produced and spin analyzed in situ. The electric field strength, precession time, magnetic shielding, and detected UCN number will all be enhanced compared to previous room temperature Ramsey measurements. Our $^3$He co-magnetometer offers unique control of systematic effects, in particular the Bloch-Siegert induced false EDM. Furthermore, there will be two distinct measurement modes: free precession and dressed spin. This will provide an important self-check of our results. Following five years of "critical component demonstration," our collaboration transitioned to a "large scale integration" phase in 2018. An overview of our measurement techniques, experimental design, and brief updates are described in these proceedings., Submitted to proceedings of PPNS 2018 - International Workshop on Particle physics at Neutron Sources (https://www.webofconferences.org/epj-web-of-conferences-forthcoming-conferences/1148-ppns-2018)
- Published
- 2019
50. Experimental approach to search for free neutron-antineutron oscillations based on coherent neutron and antineutron mirror reflection
- Author
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W. M. Snow, K.V. Protasov, Valery Nesvizhevsky, V. Gudkov, A. Yu. Voronin, Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
- Subjects
Quark ,anti-n: transverse momentum ,Particle physics ,cosmological model ,transverse momentum: low ,General Physics and Astronomy ,baryogenesis ,transverse momentum ,Antineutron ,7. Clean energy ,01 natural sciences ,Upper and lower bounds ,Computer Science::Digital Libraries ,quark ,phase shift ,Baryon asymmetry ,0103 physical sciences ,conservation law ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,Neutron ,010306 general physics ,mirror ,Computer Science::Databases ,oscillation: time ,Physics ,Annihilation ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,nucleus ,baryon number ,sensitivity ,n anti-n: annihilation ,anti-n ,oscillation: (n anti-n) ,coherence ,Baryogenesis ,Automatic Keywords ,annihilation ,Phase space ,[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] ,baryon: asymmetry ,n: transverse momentum ,Elementary Particles and Fields ,proposed experiment ,reflection - Abstract
An observation of neutron-antineutron oscillations (n−n¯), which violate both B and B−L conservation, would constitute a scientific discovery of fundamental importance to physics and cosmology. A stringent upper bound on its transition rate would make an important contribution to our understanding of the baryon asymmetry of the Universe by eliminating the postsphaleron baryogenesis scenario in the light quark sector. We show that one can design an experiment using slow neutrons that in principle can reach the required sensitivity of τn−n¯∼1010 s in the oscillation time, an improvement of ∼104 in the oscillation probability relative to the existing limit for free neutrons. The improved statistical accuracy needed to reach this sensitivity can be achieved by allowing both the neutron and antineutron components of the developing superposition state to coherently reflect from mirrors. We present a quantitative analysis of this scenario and show that, for sufficiently small transverse momenta of n/n¯ and for certain choices of nuclei for the n/n¯ guide material, the relative phase shift of the n and n¯ components upon reflection and the n¯ annihilation rate can be small enough to maintain sufficient coherence to benefit from the greater phase space acceptance the mirror provides.
- Published
- 2019
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