Parity nonconservation in polarized-neutron transmission through sup 139 La

Journal Article · Fri Nov 01 04:00:00 EST 1991 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.44.2187· OSTI ID:5025183

Yuan, V W; Bowman, C D; Bowman, J D; Bush, J E; Delheij, P P.J.; Frankle, C M; Gould, C R; Haase, D G; Knudson, J N; Mitchell, G E; Penttilae, S; Postma, H; Roberson, N R; Seestrom, S J; Szymanski, J J; Zhu, X ^[1]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico (USA) North Carolina State University, Raleigh, North Carolina (USA) Triangle Universities Nuclear Laboratory, Durham, North Carolina (USA) TRIUMF, Vancouver, British Columbia (Canada) University of Technology, Delft, The Netherlands Duke University, Durham, North Carolina (USA)

Parity nonconservation has been studied in the transmission of longitudinally polarized epithermal neutrons incident upon a {sup 139}La target. Previous experiments have demonstrated the existence of a large value of the longitudinal asymmetry in the 0.734-eV {ital p}-wave resonance of the compound nucleus {sup 140}La, but report conflicting values for the measured asymmetry. We report the results of an experiment at the Los Alamos Neutron Scattering Center (LANSCE) which measured the asymmetry by two independent methods. One of these methods utilizes a conventional polarizer and a single lanthanum target. The other method uses an unpolarized beam with two lanthanum targets, and therefore does not require a separate measurement of the beam polarization. The asymmetry values determined from these two methods (0.1015{plus minus}0.0045 and 0.0955{plus minus}0.0035, respectively) are compared to previously measured values. Measurement of the asymmetry of the 0.734-eV resonance in {sup 139}La provides a highly accurate method of determining the polarization of an epithermal neutron beam.

• DOE Contract Number: AC05-76ER01067; FG05-88ER40441; W-7405-ENG-36
• OSTI ID: 5025183
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 44:5; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651720* -- Nuclear Properties & Reactions
A=90-149
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASYMMETRY
BARYON REACTIONS
BARYONS
BEAMS
ELEMENTARY PARTICLES
EPITHERMAL NEUTRONS
FERMIONS
HADRON REACTIONS
HADRONS
INELASTIC SCATTERING
INVARIANCE PRINCIPLES
LANTHANUM 139 TARGET
NEUTRON REACTIONS
NEUTRONS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEONS
P INVARIANCE
P WAVES
PARTIAL WAVES
POLARIZED BEAMS
RESONANCE SCATTERING
SCATTERING
TARGETS