Parity violating neutron spin rotation in 4He and H
Por:
Snow W.M., Anderson E., Barrón-Palos L., Bass C.D., Bass T.D., Crawford B.E., Fry J., Gan K., Heckel B.R., Luo D., Malone R.C., Markoff D.M., Micherdzinska A.M., Mumm H.P., Nico J.S., Opper A.K., Penn S., Santra S., Sarsour M., Sharapov E.I., Swanson H.E., Van Sciver S., Walbridge S.B., Zhumabekova V.
Publicada:
1 ene 2012
Resumen:
The weak interaction between nucleons leads to parity violation in various reaction observables. Neutron spin rotation, the rotation of the plane of polarization of a transversely polarized neutron beam passing through unpolarized matter, is an especially clear example of a breakdown in mirror symmetry. The Neutron Spin Rotation (NSR) Collaboration is engaged in an experimental program to observe parity-odd neutron spin rotation. We recently completed the first phase of an experiment to measure parity violating neutron spin rotation in 4He. Our result for the neutron spin rotation angle per unit length in 4He, d?/dz = (+1.7 ± 9.1(stat.) ± 1.4(sys.)) × 10-7 rad/m, is the most sensitive search for neutron weak optical activity yet performed and represents a significant advance in precision in comparison to past measurements in heavy nuclei. This experiment was performed at the NG-6 slow neutron beamline at the National Institute of Standards and Technology (NIST) Center for Neutron Research. The systematic uncertainty is small enough to proceed to the second phase of the 4He measurement at the new NG-C slow neutron beamline under construction at NIST. The projected intensity of this beam is high enough to see parity odd neutron spin rotation in 4He and to seriously consider a future experiment to measure neutron spin rotation in hydrogen. © Società Italiana di Fisica.
Filiaciones:
Snow W.M.:
Indiana University/CEEM, 2401 Milo B. Sampson Lane, Bloomington, IN 47408, United States
Anderson E.:
Indiana University/CEEM, 2401 Milo B. Sampson Lane, Bloomington, IN 47408, United States
Barrón-Palos L.:
Universidad Nacional Autónoma de México, C.P. 04510, Mexico, D.F., Mexico
Bass C.D.:
Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606, United States
Bass T.D.:
Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606, United States
Crawford B.E.:
Gettysburg College, 300 North Washington Street, Gettysburg, PA 17325, United States
Fry J.:
Indiana University/CEEM, 2401 Milo B. Sampson Lane, Bloomington, IN 47408, United States
Gan K.:
University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
Heckel B.R.:
University of Washington/CENPA, Box 354290, Seattle, WA 98195, United States
Luo D.:
Indiana University/CEEM, 2401 Milo B. Sampson Lane, Bloomington, IN 47408, United States
Malone R.C.:
Gettysburg College, 300 North Washington Street, Gettysburg, PA 17325, United States
Markoff D.M.:
North Carolina Central University/TUNL, 1801 Fayetteville Street, Durham, NC 27707, United States
Micherdzinska A.M.:
George Washington University, 725 21st Street NW, Washington, DC 20052, United States
Mumm H.P.:
National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, United States
Nico J.S.:
National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, United States
Opper A.K.:
George Washington University, 725 21st Street NW, Washington, DC 20052, United States
Penn S.:
Hobart William Smith College, Geneva, NY 14456, United States
Santra S.:
Bhabha Atomic Research Center, Trombay, Mumbai 400085, India
Sarsour M.:
Georgia State University, 29 Peachtree Center Avenue, Atlanta, GA 30303-4106, United States
Sharapov E.I.:
Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Russian Federation
Swanson H.E.:
University of Washington/CENPA, Box 354290, Seattle, WA 98195, United States
Van Sciver S.:
National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac, Dr. Tallahassee, FL 32310-3706, United States
Walbridge S.B.:
Indiana University/CEEM, 2401 Milo B. Sampson Lane, Bloomington, IN 47408, United States
Zhumabekova V.:
Al-Farabi Kazakh National University, Al-Farabi Ave. 71, 050038 Almaty, Kazakhstan
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