Measurement of parity-violating gamma-ray asymmetry in the capture of polarized cold neutrons on protons
Por:
Gericke M.T., Alarcon R., Balascuta S., Barrón-Palos L., Blessinger C., Bowman J.D., Carlini R.D., Chen W., Chupp T.E., Crawford C., Covrig S., Dabaghyan M., Fomin N., Freedman S.J., Gentile T.R., Gillis R.C., Greene G.L., Hersman F.W., Ino T., Jones G.L., Lauss B., Leuschner M., Lozowski W.R., Mahurin R., Masuda Y., Mei J., Mitchell G.S., Muto S., Nann H., Page S.A., Penttilä S.I., Ramsay W.D., Salas-Bacci A., Santra S., Sharma M., Seo, PN, Sharapov E.I., Smith T.B., Snow W.M., Wilburn W.S., Yuan V.
Publicada:
31 ene 2011
Categoría:
Nuclear and High Energy Physics
Resumen:
The NPDGamma collaboration reports results from the first phase of a measurement of the parity violating up-down asymmetry A(gamma) with respect to the neutron spin direction of gamma rays emitted in the reaction (n) over right arrow + p -> d + gamma using the capture of polarized cold neutrons on the protons in a liquid parahydrogen target. One expects parity-odd effects in the hadronic weak interaction between nucleons to be induced by the weak interaction between quarks. A(gamma) in (n) over right arrow + p -> d + gamma is dominated by a Delta I = 1, (3)S(1)-(3)P(1) parity-odd transition amplitude in the n-p system. The first phase of the measurement was completed at the Los Alamos Neutron Science Center spallation source (LANSCE), with the result A(gamma) = [-1.2 +/- 2.1 (stat.) +/- 0.2 (sys.)] x 10(-7). We also report the first measurement of an upper limit for the parity-allowed left-right asymmetry in this reaction, with the result A(gamma,LR) = [-1.8 +/- 1.9 (stat.) +/- 0.2 (sy
Filiaciones:
Gericke M.T.:
University of Manitoba, Winnipeg, MB R3T 2N2, Canada
Alarcon R.:
Arizona State University, Tempe, AZ 85287, United States
Balascuta S.:
Arizona State University, Tempe, AZ 85287, United States
Barrón-Palos L.:
Univ Nacl Autonoma Mexico, Mexico City 04510, DF, Mexico
Blessinger C.:
Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
Bowman J.D.:
Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
Carlini R.D.:
Thomas Jefferson National Accelerator Facility, Newport News, VA 23606, United States
Chen W.:
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, United States
Chupp T.E.:
University of Michigan, Ann Arbor, MI 48104, United States
Crawford C.:
University of Kentucky, Lexington, KY 40506, United States
Covrig S.:
Thomas Jefferson National Accelerator Facility, Newport News, VA 23606, United States
Dabaghyan M.:
University of New Hampshire, Durham, NH 03824, United States
Fomin N.:
University of Tennessee, Knoxville, TN 37996, United States
Freedman S.J.:
University of California, Berkeley, CA 94720-7300, United States
Gentile T.R.:
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, United States
Gillis R.C.:
Indiana University, Bloomington, IN 47405, United States
Center for the Exploration of Energy and Matter, Bloomington, IN 47408, United States
Greene G.L.:
Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
University of Tennessee, Knoxville, TN 37996, United States
Hersman F.W.:
University of New Hampshire, Durham, NH 03824, United States
Ino T.:
High Energy Accelerator Research Organization (KEK), Tukuba-shi, 305-0801, Japan
Jones G.L.:
Hamilton College, Clinton, NY 13323, United States
Lauss B.:
Paul Scherrer Institut, CH-5232 Villigen, Switzerland
Leuschner M.:
Procure Treatment Center, 420 N. Walnut St., Bloomington, IN 47404-3803, United States
Lozowski W.R.:
Indiana University, Bloomington, IN 47405, United States
Center for the Exploration of Energy and Matter, Bloomington, IN 47408, United States
Mahurin R.:
University of Manitoba, Winnipeg, MB R3T 2N2, Canada
Thomas Jefferson National Accelerator Facility, Newport News, VA 23606, United States
Masuda Y.:
High Energy Accelerator Research Organization (KEK), Tukuba-shi, 305-0801, Japan
Mei J.:
Thomas Jefferson National Accelerator Facility, Newport News, VA 23606, United States
Mitchell G.S.:
Department of Biomedical Engineering, University of California, Davis, CA 95616, United States
Muto S.:
High Energy Accelerator Research Organization (KEK), Tukuba-shi, 305-0801, Japan
Nann H.:
Indiana University, Bloomington, IN 47405, United States
Center for the Exploration of Energy and Matter, Bloomington, IN 47408, United States
Page S.A.:
University of Manitoba, Winnipeg, MB R3T 2N2, Canada
Penttilä S.I.:
Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
Ramsay W.D.:
University of Manitoba, Winnipeg, MB R3T 2N2, Canada
TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
Salas-Bacci A.:
Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Santra S.:
Bhabha Atomic Research Center, Trombay, Mumbai 400085, India
Sharma M.:
University of Michigan, Ann Arbor, MI 48104, United States
Sharapov E.I.:
Joint Institute for Nuclear Research, Dubna, Russian Federation
Smith T.B.:
University of Dayton, Dayton, OH 45469, United States
Snow W.M.:
Indiana University, Bloomington, IN 47405, United States
Center for the Exploration of Energy and Matter, Bloomington, IN 47408, United States
Wilburn W.S.:
Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Yuan V.:
Los Alamos National Laboratory, Los Alamos, NM 87545, United States
All Open Access, Bronze
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