Pion scattering to 4/sup -/ states in /sup 14/C

Journal Article · Fri Mar 01 04:00:00 EST 1985 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.31.957· OSTI ID:5967343

Holtkamp, D B; Seestrom-Morris, S J; Dehnhard, D; Baer, H W; Morris, C L; Greene, S J; Harvey, C J; Kurath, D; Carr, J A

Angular distributions and excitation functions for inelastic scattering of..pi../sup +/ and ..pi../sup -/ from /sup 14/C were measured at incident pion energies near the ..delta../sub 33/ resonance. Three states at excitation energies 11.7, 15.2, and 17.3 MeV were identified as 4/sup -/ states. Isovector and isoscalar spectroscopic amplitudes Z/sub 0/ and Z/sub 1/, and equivalently, neutron and proton amplitudes Z/sub n/ and Z/sub p/ were deduced by comparison with microscopic distorted wave impulse approximation calculations. The 11.7-MeV state was found to be excited with a Z/sub n//Z/sub p/ amplitude ratio of -1/3, resulting in a complete cancellation of the ..pi../sup +/ cross section. A nearly pure proton excitation was observed for the transition to the 17.3-MeV state. Both results are in qualitative agreement with the presented shell-model calculations. A poor correspondence with theory is found for the 15.2-MeV state. Data and distorted-wave impulse approximation calculations using shell-model wave functions are presented for the first 3/sup -/ state at 6.73 MeV as an example of a transition dominated by ..delta..S = 0 (no spin transfer). Its excitation function and angular-distribution shape contrast sharply with the transitions to the 4/sup -/ states that proceed by ..delta..S = 1.

• Research Organization: University of Minnesota, Minneapolis, Minnesota 55455
• OSTI ID: 5967343
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 31:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 14
CARBON 14 TARGET
CARBON ISOTOPES
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DIFFERENTIAL CROSS SECTIONS
DISTORTED WAVE THEORY
DISTRIBUTION
ENERGY LEVELS
ENERGY RANGE
EVEN-EVEN NUCLEI
EXCITATION FUNCTIONS
EXPERIMENTAL DATA
FUNCTIONS
HADRON REACTIONS
IMPULSE APPROXIMATION
INELASTIC SCATTERING
INFORMATION
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
MESON REACTIONS
MEV RANGE
MEV RANGE 100-1000
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
OPTICAL MODELS
PARITY
PARTICLE PROPERTIES
PION MINUS REACTIONS
PION PLUS REACTIONS
PION REACTIONS
RADIOISOTOPES
SCATTERING
SHELL MODELS
SPIN
TARGETS
YEARS LIVING RADIOISOTOPES