NPDGamma: A Measurement of the Parity-Violating Gamma Asymmetry A in n-p Capture
Abstract
The NPDGamma Experiment measures the parity-violating correlation A{sub {Gamma}Y} between neutron spin and photon momentum in the reaction {rvec n} + p {yields} d + {gamma}. Knowledge of A{sub {Gamma}Y} and other parity-violating observables in few-body nuclear systems will provide constraints for a parameterized description of {Delta}S = 0 parity-violating phenomena free from complications of nuclear structure. The NPDGamma experiment uses a polarized cold pulsed neutron beam, a liquid parahydrogen target, and a cylindrical array of 48 CsI(Tl) scintillation detectors operated in current mode to search for the asymmetry. NPDGamma recently completed the first phase of the program to measure A{sub {Gamma}Y} at the Los Alamos Neutron Science Center with the preliminary result A{sub {Gamma}Y} = (-1.2 {+-} 2.1(stat.) {+-} 0.1(sys.)) x 10{sup -7}, reproducing the previous upper limit from a measurement at a reactor facility. We discuss the theoretical background and experimental method and report on preliminary analysis of the LANSCE data. The second phase of the program to measure A{sub {Gamma}Y} is in progress at the Spallation Neutron Source at Oak Ridge National Laboratory.
- Authors:
-
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- Indiana University
- Arizona State University
- Arizona State University & Univ. Nacional Autonoma de Mexico
- ORNL
- Thomas Jefferson National Accelerator Facility
- University of Michigan
- University of Kentucky, Lexington
- University of New Hampshire
- University of Tennessee, Knoxville (UTK)
- University of California, Berkeley
- National Institute of Standards and Technology (NIST), Gaithersburg, MD
- University of Manitoba, Canada
- University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)
- High Energy Accelerator Research Organization, KEK
- Hamilton College, New York
- Paul Scherrer Institut, Villigen, Switzerland
- University of Manitoba & Thomas Jefferson National Accelerator Facility
- University of California, Davis
- Oak Ridge National Laboratory (ORNL)
- TRIUMF, Canada
- Los Alamos National Laboratory (LANL)
- North Carolina State University
- Joint Institute for Nuclear Research, Dubna, Russia
- University of Dayton, Ohio
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1017365
- DOE Contract Number:
- DE-AC05-00OR22725
- Resource Type:
- Journal Article
- Journal Name:
- Journal of Physics Conference Series
- Additional Journal Information:
- Journal Volume: 239; Journal Issue: 1; Journal ID: ISSN 1742--6596
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; NEUTRON BEAMS; NEUTRON SOURCES; NEUTRONS; NUCLEAR PHYSICS; NUCLEAR STRUCTURE; ORNL; PHOTONS; SCINTILLATION COUNTERS; SPALLATION; SPIN
Citation Formats
Gillis, R. C., Alarcon, R., Balascuta, S., Barron-Palos, L., Bowman, James D, Carlini, R. D., Chen, W., Chupp, T. E., Crawford, C., Covrig, S., Dabaghyan, M., Fomin, N., Freedman, S., Gentile, T. R., Gericke, M. T., Greene, G., Hersman, F. W., Ino, T., Jones, G., Lauss, B., Leuschner, M., Lozowski, W. R., Mahurin, R., Masuda, Y., Mei, J., Mitchell, G. S., Muto, S., Nann, H., Page, S. A., Penttila, Seppo, Ramsay, W. D., Salas-Bacci, A., Santra, S., Sharma, M., Seo, P. -N., Sharapov, E. I., Smith, T. B., Snow, W. M., Wilburn, W. S., and Yuan, V. NPDGamma: A Measurement of the Parity-Violating Gamma Asymmetry A in n-p Capture. United States: N. p., 2010.
Web. doi:10.1088/1742-6596/239/1/012012.
Gillis, R. C., Alarcon, R., Balascuta, S., Barron-Palos, L., Bowman, James D, Carlini, R. D., Chen, W., Chupp, T. E., Crawford, C., Covrig, S., Dabaghyan, M., Fomin, N., Freedman, S., Gentile, T. R., Gericke, M. T., Greene, G., Hersman, F. W., Ino, T., Jones, G., Lauss, B., Leuschner, M., Lozowski, W. R., Mahurin, R., Masuda, Y., Mei, J., Mitchell, G. S., Muto, S., Nann, H., Page, S. A., Penttila, Seppo, Ramsay, W. D., Salas-Bacci, A., Santra, S., Sharma, M., Seo, P. -N., Sharapov, E. I., Smith, T. B., Snow, W. M., Wilburn, W. S., & Yuan, V. NPDGamma: A Measurement of the Parity-Violating Gamma Asymmetry A in n-p Capture. United States. https://doi.org/10.1088/1742-6596/239/1/012012
Gillis, R. C., Alarcon, R., Balascuta, S., Barron-Palos, L., Bowman, James D, Carlini, R. D., Chen, W., Chupp, T. E., Crawford, C., Covrig, S., Dabaghyan, M., Fomin, N., Freedman, S., Gentile, T. R., Gericke, M. T., Greene, G., Hersman, F. W., Ino, T., Jones, G., Lauss, B., Leuschner, M., Lozowski, W. R., Mahurin, R., Masuda, Y., Mei, J., Mitchell, G. S., Muto, S., Nann, H., Page, S. A., Penttila, Seppo, Ramsay, W. D., Salas-Bacci, A., Santra, S., Sharma, M., Seo, P. -N., Sharapov, E. I., Smith, T. B., Snow, W. M., Wilburn, W. S., and Yuan, V. Fri .
"NPDGamma: A Measurement of the Parity-Violating Gamma Asymmetry A in n-p Capture". United States. https://doi.org/10.1088/1742-6596/239/1/012012.
@article{osti_1017365,
title = {NPDGamma: A Measurement of the Parity-Violating Gamma Asymmetry A in n-p Capture},
author = {Gillis, R. C. and Alarcon, R. and Balascuta, S. and Barron-Palos, L. and Bowman, James D and Carlini, R. D. and Chen, W. and Chupp, T. E. and Crawford, C. and Covrig, S. and Dabaghyan, M. and Fomin, N. and Freedman, S. and Gentile, T. R. and Gericke, M. T. and Greene, G. and Hersman, F. W. and Ino, T. and Jones, G. and Lauss, B. and Leuschner, M. and Lozowski, W. R. and Mahurin, R. and Masuda, Y. and Mei, J. and Mitchell, G. S. and Muto, S. and Nann, H. and Page, S. A. and Penttila, Seppo and Ramsay, W. D. and Salas-Bacci, A. and Santra, S. and Sharma, M. and Seo, P. -N. and Sharapov, E. I. and Smith, T. B. and Snow, W. M. and Wilburn, W. S. and Yuan, V.},
abstractNote = {The NPDGamma Experiment measures the parity-violating correlation A{sub {Gamma}Y} between neutron spin and photon momentum in the reaction {rvec n} + p {yields} d + {gamma}. Knowledge of A{sub {Gamma}Y} and other parity-violating observables in few-body nuclear systems will provide constraints for a parameterized description of {Delta}S = 0 parity-violating phenomena free from complications of nuclear structure. The NPDGamma experiment uses a polarized cold pulsed neutron beam, a liquid parahydrogen target, and a cylindrical array of 48 CsI(Tl) scintillation detectors operated in current mode to search for the asymmetry. NPDGamma recently completed the first phase of the program to measure A{sub {Gamma}Y} at the Los Alamos Neutron Science Center with the preliminary result A{sub {Gamma}Y} = (-1.2 {+-} 2.1(stat.) {+-} 0.1(sys.)) x 10{sup -7}, reproducing the previous upper limit from a measurement at a reactor facility. We discuss the theoretical background and experimental method and report on preliminary analysis of the LANSCE data. The second phase of the program to measure A{sub {Gamma}Y} is in progress at the Spallation Neutron Source at Oak Ridge National Laboratory.},
doi = {10.1088/1742-6596/239/1/012012},
url = {https://www.osti.gov/biblio/1017365},
journal = {Journal of Physics Conference Series},
issn = {1742--6596},
number = 1,
volume = 239,
place = {United States},
year = {2010},
month = {1}
}