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Title: The 2004 NPDGamma Commissioning Run-Measurement of Parity-Violating Gamma-Ray Asymmetries in Neutron Capture on Al, Cu, Cl, In, and B

Abstract

The NPDGamma experiment will measure with a high precision, 5x10-9, the small parity-violating gamma-ray asymmetry, A{gamma}, in polarized cold neutron capture in a para-hydrogen target to determine unambiguously the weak pion-nucleon coupling constant H{sub {pi}}{sup 1}. For the experiment the collaboration has built a new high-flux pulsed cold neutron beam line at LANSCE. In 2004, we first commissioned the beam line and then the apparatus with exception of the hydrogen target. The sensitivity of the apparatus was tested by measuring A{gamma} on Al, B, Cl, Cu, and In. The Cl has a well-known large parity-violating gamma-ray asymmetry that was used to verify the performance of the apparatus. The other nuclei that were studied during the commissioning run are present in materials used for construction of the experiment and are, therefore, possible sources of the false asymmetries since backgrounds are expected to be about 10% of the signal from the neutron capture on hydrogen. We measured A{gamma}{approx_equal}0 for these nuclei except for Cl. We report the status of the experiment and preliminary results of the 2004 commissioning run.

Authors:
; ; ; ; ;  [1];  [2]; ;  [3]; ; ;  [4]; ; ; ; ; ;  [5]; ;  [6]
  1. Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
  2. Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)
  3. Department of Physics, University of Michigan, Ann Arbor, MI 48104 (United States)
  4. Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)
  5. Department of Physics, Indiana University, Bloomington, IN 47405 (United States)
  6. Department of Physics, University of Tennessee, Knoxville, TN 37996 (United States); and others
Publication Date:
OSTI Identifier:
20722657
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 769; Journal Issue: 1; Conference: International conference on nuclear data for science and technology, Santa Fe, NM (United States), 26 Sep - 1 Oct 2004; Other Information: DOI: 10.1063/1.1945104; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ALUMINIUM; ASYMMETRY; BORON; CAPTURE; CHLORINE; COLD NEUTRONS; COPPER; GAMMA RADIATION; HYDROGEN; INDIUM; NEUTRON REACTIONS; PARITY; PERFORMANCE; PION-NUCLEON INTERACTIONS; SENSITIVITY

Citation Formats

Seo, P -N, Bowman, J D, Mitchell, G S, Penttilae, S I, Wilburn, W S, Yuan, V, Carlini, R D, Chupp, T E, Coulter, K P, Dabaghyan, M, Hersman, F W, Zhu, H, Dawkins, M, Leuschner, M B, Lozowski, B, Nann, H, Santra, S, Snow, W M, Desai, D, and Mahurin, R. The 2004 NPDGamma Commissioning Run-Measurement of Parity-Violating Gamma-Ray Asymmetries in Neutron Capture on Al, Cu, Cl, In, and B. United States: N. p., 2005. Web. doi:10.1063/1.1945104.
Seo, P -N, Bowman, J D, Mitchell, G S, Penttilae, S I, Wilburn, W S, Yuan, V, Carlini, R D, Chupp, T E, Coulter, K P, Dabaghyan, M, Hersman, F W, Zhu, H, Dawkins, M, Leuschner, M B, Lozowski, B, Nann, H, Santra, S, Snow, W M, Desai, D, & Mahurin, R. The 2004 NPDGamma Commissioning Run-Measurement of Parity-Violating Gamma-Ray Asymmetries in Neutron Capture on Al, Cu, Cl, In, and B. United States. https://doi.org/10.1063/1.1945104
Seo, P -N, Bowman, J D, Mitchell, G S, Penttilae, S I, Wilburn, W S, Yuan, V, Carlini, R D, Chupp, T E, Coulter, K P, Dabaghyan, M, Hersman, F W, Zhu, H, Dawkins, M, Leuschner, M B, Lozowski, B, Nann, H, Santra, S, Snow, W M, Desai, D, and Mahurin, R. Tue . "The 2004 NPDGamma Commissioning Run-Measurement of Parity-Violating Gamma-Ray Asymmetries in Neutron Capture on Al, Cu, Cl, In, and B". United States. https://doi.org/10.1063/1.1945104.
@article{osti_20722657,
title = {The 2004 NPDGamma Commissioning Run-Measurement of Parity-Violating Gamma-Ray Asymmetries in Neutron Capture on Al, Cu, Cl, In, and B},
author = {Seo, P -N and Bowman, J D and Mitchell, G S and Penttilae, S I and Wilburn, W S and Yuan, V and Carlini, R D and Chupp, T E and Coulter, K P and Dabaghyan, M and Hersman, F W and Zhu, H and Dawkins, M and Leuschner, M B and Lozowski, B and Nann, H and Santra, S and Snow, W M and Desai, D and Mahurin, R},
abstractNote = {The NPDGamma experiment will measure with a high precision, 5x10-9, the small parity-violating gamma-ray asymmetry, A{gamma}, in polarized cold neutron capture in a para-hydrogen target to determine unambiguously the weak pion-nucleon coupling constant H{sub {pi}}{sup 1}. For the experiment the collaboration has built a new high-flux pulsed cold neutron beam line at LANSCE. In 2004, we first commissioned the beam line and then the apparatus with exception of the hydrogen target. The sensitivity of the apparatus was tested by measuring A{gamma} on Al, B, Cl, Cu, and In. The Cl has a well-known large parity-violating gamma-ray asymmetry that was used to verify the performance of the apparatus. The other nuclei that were studied during the commissioning run are present in materials used for construction of the experiment and are, therefore, possible sources of the false asymmetries since backgrounds are expected to be about 10% of the signal from the neutron capture on hydrogen. We measured A{gamma}{approx_equal}0 for these nuclei except for Cl. We report the status of the experiment and preliminary results of the 2004 commissioning run.},
doi = {10.1063/1.1945104},
url = {https://www.osti.gov/biblio/20722657}, journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 769,
place = {United States},
year = {2005},
month = {5}
}